Backup Error 0x81000038 In Windows 7 [KB981907]

One of my clients was getting error 0x81000038 whenever she started the backup tool in Windows 7. She said that whatever she selected, whether internal drives or external drives, she was getting the same error. She restarted the system but to no avail.

I searched the internet for any possible solutions and got the KB981907 from Microsoft Knowledgebase. This problem occurs when the AppData key in the registry is missing or corrupt for the currently logged in user. This error is user specific so if there are 10 user accounts in one system and all of them are getting the same error 0x81000038, all of them need to fix their AppData key in the registry.

In fact there are two solutions to this problem, one is a temporary fix and the other one is the permanent one.

Solution 1: Select AppData folder manually when backing up

By default, Windows backup and restore tool includes the AppData folder for the backup. We can uncheck the AppData folder from the default selection list and then specify it by browsing the actual path to the AppData folder. To do this, follow these steps:

  1. In Backup and Restore, click Change settings, select a backup destination, and then click Next.
  2. Select Let me choose, and then click Next.
  3. Expand Data Files, and then clear AppData folder under Additional Locations for each user account.
  4. Expand Computer, expand the system disk, expand Users, and then expand each users account to reselect AppData.
  5. Follow the instructions.

appdata folder


Solution 2: Edit the registry to fix the correct AppData folder path

  1. For every user on your machine, Login as the user Run -> regedit.exe
  2. Go to the following key:
    HKEY_CURRENT_USER\Sofware\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
  3. Observe the value of Appdata and LocalAppdata. If it has an empty value or a value of the type %Appdata%, this is the culprit. Can you verify that this is the case with your machine?
  4. If so, the workaround is the following:
    • Open a command prompt
    • Type set Appdata / LocalAppdata depending on which registry entry has the wrong value. If Appdata is wrong, type set Appdata and if Local Appdata is wrong, type set LocalAppdata.
    • Copy the value after the = sign. Example if the output is: APPDATA=C:\Users\Sanix\Appdata\Roaming, copy the value C:\Users\John\Appdata\Roaming
    • Paste the value in the wrong registry value. Either replace the %<<<>>>% value or fill the empty value.
  5. Run backup again. It should succeed.