-The home of Cobian Backup


Frequently Asked Questions (FAQ)

Q: Does Cobian Backup work in Windows 8 and 10?
Yes, it works just fine in Windows 8 and 10. You will need to activate/install the .NET 3.5 framework in order to be able to use Volume Shadow Copies. .NET 3.5 is present on Windows 8 and 10 but not active. In order to activate it just open the Control Panel, Click Programs, Click Turn Windows Features on or off and select the .NET 3.5 framework. Do this before installing the program and everything will be working fine.

Q: Is Cobian Backup still under development?
Well, I sold the source code back in 2014 to James Sweeney. I haven't heard anything from him since then so I don't know about his plans. I am thinking about creating a whole new different backup product. It will be nothing like Cobian Backup, but it will have many of CB features.

Update: the new backup product is called Cobian Reflector and is now available on this site.

Q: I have a question about Cobian Backup. What can I do?
Please use the Support forum that you find under the Help menu. Do NOT ask me questions privately by mail, they may never get answered.

Q: Can I use old 3.x and 4.x, 5.x, 6.x and 7.x lists?
A: Click the menu List-Import to convert the old format into the new one. The old items will be added to your current list. In this version, only lists that have been created by versions 6,7 and 8 can be imported.

Q: I keep getting a "Engine no found error" Why?
if you get the error The engine is not found followed by "The engine has been found" then this is a completely normal event. When the user interface is started, it checks to see if the engine (the service) is started. When the computer is started it can take some time until the service get started, so you can ignore this error. Now, if the "Engine is not found" error is the only one you get and the mushroom in the tray has a light red background, the you have a problem. Things to check:

1) If the program is installed as a service, then this means that the service has not been started. Often this is caused by a login error. If the service is set up to start under some account, and you entered the wrong password then you will find the description of the error in the EventViewer. Just re-enter the user name and the correct password and restart the service. This can be done from the control panel or from the user interface (Options-General-Service and Application control)

2) Another possibility is that you are trying to start the service under an account that has an empty password. The default policy in some Windows versions is that a service cannot be started with an empty password.

3) If the program has been working fine for some time and suddenly you are getting the "Engine not found" error, you probably have changed the password of the account that is running the service. Just re-enter the new password in Options-General-Service and Application control and restart the service.

4) Another possibility is that the service (or the application engine) is crashing for some reason.

Q: My favorite unpacker cannot open zip files created by the program. Why?
The standard zip format has changed a lot the last years. Some extensions have been added to handle Unicode file names, large files (zip 64), etc. Unfortunately not all archivers support them (or they support them partially). Cobian Backup creates zip files that are 100% compatible with the latest version of Winzip. The included decompressor should also handle these files without problems. Other archivers may or may not support all new extensions so you may get errors like "Archive corrupted" or "Unexpected end of the archive".

Q: When I click "Run all tasks" nothing happens. Why?
First, check is the engine is running. If the engine is present, you may be experimenting problems with your permissions. Run the utility "Repair permissions" which you find under your Tools menu. Read more about this utility in the Help file under "Menu-Tools".

Q- I'm trying to impersonate a user in a task but it fails. Why?
For this feature to work,, you need to use NT 4.0 SP6 or better (2000/XP/2003/Vista, etc). In some systems like Windows 2000, this function will fail because the normal user of the service/process need to have the SE_TCB_NAME privilege. This means that this will only work if the service is running under the Local System account (Windows 2000 only)

Q- In the log file I see: "Couldn't create the 7zip object. Perhaps the 7za.dll library is not available"
This error is sometimes wrongly logged, when a file system error arises if using the 7zip method. This error could be caused by a lack of space in the destination directory (or temporary folder) or by trying to create an archive larger than 2Gb on a FAT partition. Some other causes are file system errors which can be found on the Event Viewer (Event ID 50 and Event ID 26 being the most common ones, and seems to be a service pack 3 issue in XP )

Q- I want to include the %TASKNAME parameter in the subject of the mail
The mails are send per backup, not per task, so the %TASKNAME parameter would have no meaning in the subject.

Q- I am compressing/encrypting to several destinations in the same task. The program compresses and encrypts twice. Isn't that ineffective?
Yes, it's ineffective but the solution for this case is: split the task in two: the first task should compress/encrypt the source into the first destination. The second task should plain copy the results of the first task to the second destination.

Q:- My network backup is extremely slow
Try disabling the "Copy timestamp", "Copy attributes" and "Copy NTFS permissions" options.

Q- I get a popup window when the interface starts. It says something like "Opening or  launching Welcome.htm (v. 8) or External.htm". Why? How do I fix that?
This is caused sometimes by some browser (often Firefox) which has been installed and some registry settings have been incorrectly set. There are several fixes for this problem. The easiest one is to make IE your default browser temporarily then switch back to Firefox.

Other solutions involving registry editing can be found here: 

Q- When using absolute paths and automatic deletion, my files are deleted but not the long path. Why?
This is by design because the program cannot be sure that other tasks ara not using the same destination. Imaging that you have Tas1, with source c:\dir\1 and destination d:\. Task 2 will have source c:\dir\2 and destination d:\.

Then, the created structure after running BOTH tasks will be d:\c\dir\2 and d:\c\dir\1 .

If then task 1 removes d:\c, the all files from the second task will be removed as well.

Q- How do I know which backups are full, which are incremental, etc? Could you add the backup type to the file names?
 Unfortunately, the design of the program doesn't allow adding the backup type to the file names easily at this moment. I recommend you to backup your backup history as well. This way, you can know which backup is which, in case of disaster.

Q: When using VSS I get an error in Windows event viewer: "Unexpected error GetVolumeNameForVolumeMountPointW "
This error is not fatal and can be ignored. The cause of this error could be that there is some problems with permissions or that there are some programs like Daemon Tools creating some virtual drives that can confuse the VSS system.

Q: When impersonating an user and using VSS, the program logs on the impersonated user twice. Why? Isn't that inefficient?
Yes, it's kind of inefficient. The program impersonates the user first, then it runs the before-backup events and then it reverts back the thread to start VSS. When the shadow copy is  created, the program impersonates once again the user. This is done because VSS was added when the logic of the events and impersonation was already implemented in earlier versions. To make it work directly before the impersonation occurs, a complete re-design of the program would be necesary. 

Q: I cannot create a VSS snapshot or cannot use Volume Shadow Copies at all. Why?
There are several things that could cause the VSS to fail when creating a snapshot. The main problem could be permissions. The user that is executing the backup must have administration's or backup privileges to use VSS.

Then the volume that you are trying to snapshot must be supported by the system: It must be a NTFS volume (not FAT or FAT32), local (not on a remote machine) and native (not a TrueCrypt volume or some other emulated volume)

In old versions only (this doesn't apply to Version 11): Cobian Backup is a 32 bit application and, on 64 bit systems it must run under WOW64. This works fine on XP64 or Windows Server 2003 64 because 32 bit programs are allowed to call VSS from WOW64.  Vista and Windows Server 2008 don't allow that and VSS must be called as a native 64 bit application, which means that you can't use VSS from Cobian Backup on Vista 64 at this moment. A solution for this issue could be found in the future.

Q: If I have 2 tasks scheduled to start at the same time, in which order will they start? Will they run simultaneously?
No. All tasks will be run sequentially. If two tasks are scheduled to start at the same time, then the first one on the list will be executed, and when it ends, then the second one will start.

Q: I want my tasks to run simultaneously. Is that possible? If not, why not?
This was posible up to version 4. After that version all tasks are executed sequentially. The tasks are added to a queue, and executed in that order. The simultaneous execution was a good idea in theory but a very bad one in practice. When 4-5 tasks were executing at the same time, compressing and encrypting, you could hear the hard drive scream in pain. No matter how many processors, memory, broadband, etc you have. The hard drive is the bottleneck here. Unless you have one task per hard drive, you win nothing with simultaneous executions. Anyway, if you want to torture your system, you can download version 3 or 4 from my site.

Q: Why can the 7zip method update an existing archive?
I have done a partial translation of the 7zip library but I have not implemented the Update function yet. Will be done in the future.

Q: When deleting a FTP directory, hidden files are not deleted 
The problem is: to be able to delete a directory, the program must recursively delete all files and subdirectories present on the remote site. In order to do this, the program requests a list of files. Some servers can be configured to send the hidden files as well, but some others don't do that. In that case, the program will delete all other files, but not the hidden ones, and of course, the parent directory will not be deleted. Check if with your FTP server allows to send hidden files when a list command is received. For example, Proftpd can be configured to send hidden files in a listing: File : /etc/proftpd/proftpd.conf Modification : ListOptions "-1" replace by ListOptions "-A" #List all files except "." and ".." 

In version 10, you can add a parameter to force the server to send you the listing with all hidden files. Again, the server must support this.

Q: I get a "Connection refused" error when checking for new versions. Why?
It could be possible that your firewall is blocking the connection. OR it could be that the server is down. Please do NOT contact me every timme the server is down. It happens from time to time and it's extremely annoying to get 400+ letters every time it happens.

Q: In which language was Cobian Backup created?
A: Cobian Backup was completely written using Borland Delphi 2006 (Object Pascal). After version 9.5 there are some parts written in C#.

Q- I have successfully installed the program as a service. It worked fine under some weeks but now I get the error "Engine not found".
Why? This can happen if the password of the account that is running the service has changed. Use the Options dialog to change the password of the service.

Q: I want to close a program. What is the "Window Caption" that I need to enter?
A: The window caption is the place that contains the title of the window:


In this case (picture) I can enter the whole caption "Dokument1-Microsoft Word" or a part of the caption "Dokument1" or "Microsoft Word". Note that you must enter your words EXACTLY as they are found in the window (CASE SENSITIVE).

Some programs change the caption of the window depending on the document that they are using, so try to use a word that you know will be present in the caption when it's time to close the program. Another problem: there can be several windows using the same caption. In this case, only one will be closed. Try to use the exact caption as a parameter when closing programs, but you can also use only a part of the caption if you are sure that only one window contains these words.

In this version, you can also enter a window's class name. This class name cannot be easily known but if you are a programmer or an advanced user, you can use tools like Spy++ to get the class name of some window. In this case you need to enter the class name in the form:


including the word "class:" with the colon.

Q: I get a message that says that the engine is not found
There are several possibilities here. The user interface is the "dummy" program that you see in the system tray. It must communicate with the engine, that may be running as a service or as an application in the background.


1) Check if the service is running (in the case that the program was installed as a service)

2) If the program was installed as an application, re-run the program from the Start menu to be sure that the engine is running (or run the Cobian.exe executable).

Another possibility may be that you entered the wrong account name/password combination when installing the program.

To fix this problem, go to Options and try to start the service there. You can also change the logon options in the same place.

Q: My firewall says that Cobian Backup is accessing the network? Why?
Cobian Backup only uses the Internet for the Check for new versions feature. If you don't like it, just disable it.

Q: I want to translate the program into my language
A: Use the Translation tool under the menu Tools and send the 2 string files back to me.

Q: Which command line arguments can I use with Cobian Backup?
A: This version has dropped the special command line utility from older versions. Now you can use the application Cobian.exe from the command line.

The arguments are:

-nogui Don't start the user interface

-autoclose Close the program when the backup is done

-bu Backup all the tasks immediately

-list:(ListName) start the program using the list on ListName. If the list name contains spaces, surround THE WHOLE argument between quotes.

-m: Opens the interface maximized. No tray icon is shown


Cobian.exe "-list:C:\Program Files\List.lst" -bu -nogui

Other parameters can also be used. See the help file.

Q-How can I start the backup of all tasks when Windows starts? And when Windows shuts down?
Use the "Run everything on start" options. On older versions, if you are auto-starting the program, you need to edit the registry. Look at the key




Find the value named "Cobian Backup" or "Cobian Backup User interface". Edit the value adding the parameter -bu after the program name. It's not possible to start a backup when Windows shuts down because the system would kill the service in the middle of the work.

Q: Installing the program as a service, I get an error in the log file. The program cannot access a network drive. Why?
A: In order to access a network resource, the service cannot be running as the local system account. One way to fix this problem:

* Uninstall the program.

* Install it again, but select the option "Use the following account".

* Then you can enter a valid user ID and a password. This account must have permission to access the network drive.

The other way:

* Just go to the Options dialog box and re-enter the logon settings there.

Q: Why the program fails to backup some files?
A: Windows and some other programs may open some files with exclusive share access. In this case the backup program (and any other program) will fail while trying to copy this file. Solution: close the program that is using the file you are trying to backup  or acivate the Volume Shadow Copy option if possible.

Q: Is there some Recovery function?
A: Cobian Backup doesn't use any proprietary format and doesn't need a special recovery function. Just copy/unzip your files back. I don't have ANY plans to make a Recovery function. Please don't ask me about this.

Q: Why the program fails to zip? I have enough free space on the destination drive.
A: Zip operations uses the temporary directory to compress. If you doesn't have enough free space on your default temporary folder when compressing a BIG file or huge amount of data, the zip file may become corrupted. Change your temporary directory for zip files on the options dialog. Be aware that Cobian Backup uses many features in the zip files (like zip64 or Unicode file names) that many unpackers don't support. So the problem may be that your program doesn't support any of those features. Use the latest Winzip or the included Decompressor for 100% compatibility.

Q: I use a "Before backup" event to start a program before the backup starts, but I don't see the program. The log file says that the program was successfully started.
A: This information applies to version 7.3 and earlier. Starting from 7.4 the program can now start the programs in the user desktop.

You are running the program as a service. A service runs in another desktop context. The program you started IS RUNNING but it's invisible to you, because it was started by a service. You can set the service to run interactively with the desktop, but this is not recommended (this service was not designed with this in mind. Do it at your own risk.). You can also use the program as an application to solve this problem.

Q: I use a "Before backup" event to stop a program before the backup starts. The log file says that the program was no found but the program IS running.
A: This information applies to version 7.3 and earlier. Starting from 7.4 the program can now close the programs in the user desktop.

You are running the program as a service. A service runs in another desktop context. The program you want to stop is running in another desktop. You can set the service to run interactively with the desktop, but this is not recommended (this service was not designed with this in mind. Do it at your own risk.). You can also use the program as an application to solve this problem.

Q: I want your program to create a mirror for me. When I delete the original file, I want the program to delete the backup copy.
A: This is a terrible function to have in a backup program. Please do NOT ask me to add this function. Imagine what would happen if a virus deleted your files and when you go to Cobian Backup to restore the files you find out that Cobian Backup deleted the same files because it is mirroring the information! NEVER ask me to add this.

Update. In version 10, a mirror can be implemented for uncompressed local backups.

Q: I am trying to backup to a CD-RW but I get an error that says "Destination directory no found". Why?
A: This program doesn't include a driver to use with a CD burner. That's why you cannot backup directly onto a CD-RW. Backup onto your hard drive and then you can manually burn the backup onto the CD using your favorite burning software.

There are some 3rd party programs as Adaptec Direct CD (Direct Write) which can make it possible for Cobian Backup to interact directly with your CD burner. If you have this or other similar software installed, you can backup directly onto your CD.

Be aware that Cobian Backup is a multithreaded program and therefore multiple threads may be accessing your CD at the same time. When zipping, the WHOLE zip operation will go on on the destination directory, and your CD may become unreadable or corrupted. The bottom line is : do NOT backup directly into a CD-RW.

Q: Can I backup directly to a CD-DVD?
Cobian Backup does not contain burning drivers, so you must rely on 3d party drivers. It is NOT recommended to backup directly to a CD. You can use for example, DirectWrite or other tool for this. Be aware that compressing is an operation that does NOT copy the files sequentially, but creates a lot of temporary files, etc, so DO NOT compress to a CD. Copying without compression is not safe either, but if you want SO MUCH to copy directly to the CD, check the option "Always use ShFileOperation".

Q: I am having some weird errors when uploading/downloading to a FTP, or I cannot connect at all.
A: Check your firewall. It may be blocking the program. Check also that you are uploading to the right directory. So many people are leaving the Remote Directory field to the default "/". Of course, normally, nobody can upload to the root.

Q - My service cannot access my mapped drive Z:. Why?
A: Mapped drives may not be available to services. Use UNC paths instead: \\Server\Drive

Q- I get a "No enough space" when compressing, but I do have enough space in the destination.
A: You may need to have the same amount of space in your temporary directory too.

Q - Why doesn't Cobian Backup work with FastSwitch in Windows XP?
 A- The program CAN work fine with FastSwitch if there other users that are logged on the system are not running Cobian Backup at the same time.

Q- My incremental or differential backup doesn't work. The program seems to copy every file. Why?
A- Cobian Backup uses the archive bit of the attributes to check if the file has been changed or not. Sometimes the program fails to change the attribute and the file will be copied again next time even if it is not necessary. The archive attribute operation can fail for example if your source is on a Linux file system or other system that has different attribute formats or if the engine doesn't have permission to change the attribute.

Q: I can change the archive attribute manually, yet, the program cannot do the same. Why?
A - Remember that the engine can be running under a different account, for example, under LocalSystem. Change the username for the service to match your username.

Q - I want to exclude a subdirectory from several folders. For example, I have one subdirectory called Versions in every folder. How do I do?
A- Enter a mask of type: *\Versions\* or *\Versions*\* Note that the files contained in the directory will be excluded but the directory itself will be created, but empty. To prevent this, check the option "Delete empty directories". 

Q- I backup a task and everything seems to be OK. However I get a message saying that there are some errors. I don't see any other error in the log file. Why?
Some errors are non critical. For example trying to backup to a non-existing FTP directory will give you an error: the directory doesn't exist. However, the program will create the directory for you and the backup will go on. But there is a warning to you anyway. Check Verbose if you want to see ALL the messages, but be warned, the log file will become HUGE!

Q- Can Cobian Backup copy files with file names in Chinese, Japanese or other multi-byte languages?
Yes. Cobian Backup is Unicode and it will copy any file. Zip and 7zip methods store the file names as uniocode as well. The FTP protocol uses mainly ANSII too, but there is support for UTF-8 transfers.

Q: The program seems VERY slow when the interface starts up. It's eating up all my machine's resources.
A - The program is calculating the total sizes of the sources. If your sources contain a huge number of file or it is a network source, this can be time consuming. Uncheck the option: Options-Interface-Show sizes

Q- When I want to install the program, I get an error that says that the files could not be unzipped or that the resource file could not be extracted.
Things to check:

1- Check that you have enough space in your temporary directory to extract the files. 50 Mb of free space should be enough.

2) Check that you have permissions to write and create subfolders on that directory.

Q- I want to make an incremental or differential backup but the program keeps making full backups. Why?
The program uses the archive bit of the file's attribute to decide if the file has been changed and there is a need to backup the file. If the program fails to reset this attribute back after a backup, the next backup will, once again copy this file even if it has not been changed. The cause because the attribute could not be changed may have been:

 1- The user of the program doesn't have permissions to modify the attributes

2- The source files may be placed on a SMB partition which doesn't support Windows file attributes (like almost any file system on Linux, MacOS, etc) Some other causes may be: you are compressing AND encrypting without creating new backups separated by timestamps. In this case it's more effective to just do a full backup than to update.

Q- I am behind a firewall or NAT network system. What do I do to make the FTP feature to work?
The transfers work but the engine seems to freeze The FTP protocol in general is not firewall friendly, as it uses multiple socket connections to perform its work. Try putting the FTP transfers into Passive mode when performing transfers and directory listings. Passive transfers use outbound connections, which firewalls and NAT routers are more likely to allow and work with. Set the external NAT IP address in the advanced page of the FTP. If possible, check also NAT fast track. One thing to keep in mind is that not all routers/firewalls are FTP-aware. Many that are not will close an idle control connection while the data connection is busy transferring a large file. If you have control over your FTP server, try increasing the Timeout value for accepted transfers or connections. This can sometimes help, but the idling is not happening at the server anyway, but at the router/firewall when they are not FTP aware.

Q- I want to backup to a FTP. I write the address but I get a timeout. I know the address exists.
Your domain is Leave out the ftp:// protocol.

Q- I would like to backup files that are open exclusively by another application. Is this possible?
If some application is working with a file that is open exclusively, there are several things you may try to do:

1) Use VSS if you are on XP or a newer OS.

2) Use a "Before backup" event to close the application and an "After backup" event to open the application again.

3) Microsoft has a script which close all the open files. This can be used as a batch file in a "Before backup" event and seems to work OK must of the times. This works only in NT based systems, though.

Q- Is there any limit for the size of the file for strong encryption?
Not anymore after version 7.1

Q: Can I run the program without the tray icon?
If you are running the program as an application, just use the argument -nogui. As a service, just remove the "Cobian Backup Interface 7" value from the registry key:


Q: I have a zip file , created with Cobian Backup. The file cannot be open with my favorite program and is 5 GB in size. Why?
For large files (> 2Gb) the format Zip64 is used. Only a few programs support this format: WinZip 9.0 or newer, WinRAR, ZipGenius or the integrated Decompressor of Cobian Backup are a few of them.

Q: How do I exclude the Firefox Cache directory?
Add these masks to the Exclude masks: XUL.mfl Cache\_CACHE* Cache\*d01 parent.lock

Q: Why do you use the archive attribute for incremental backups and not the timestamp as in previous versions?
For many reasons, but the must important of them are: using the timestamp makes it impossible to have incremental or differential backups without overwriting the files. If you choose to NOT overwrite old backups, then the destination file will, of course never exist, and there is no file to compare the time stamp with. That's why a full backup will always occur. FTP non-full backups will also be difficult to accomplish, because the date/time format can be different depending on the OS where the FTP server is located. In this version, you CAN use timestamps. Uncheck "Use file attributes logic", but bear in mind that many features will not work with this method.

Q: My service stopped working today. Why?
If your service is running under an account different from LocalService, then if you change the password of the account, the service will fail to logon, because it tries to logon using the old password. Change the logon settings in Tool-Options.

Q: The program works fine when running as an administrator or power user in XP/2000 but it refuses to start as a normal user.
Check the NTFS security attributes of the directory where the program is located. Grant read access to everyone. Especially important are all the INI files in the subdirectory "Db". Grant read/write access to them for every user. This is especially important when running on Vista.

Q: AddAware reports libeay32.dll and ssleay32.dll to be spyware.
A: These 2 libraries are part of the OpenSSL standard used to transfer FTP files securely. If you don't use SSL and it makes you feel better, just delete the libraries.