We all must appreciate benefits of backing up. So do I, but I’ve been facing this error: 0x81000033 while doing backups (using  Backup and Restore) on my new(-ish) Windows 7 Ultimate machine.

After googling a bit I found a solution that worked. Seems that the problem was because of the size of USN journal that was turned-on on System Reserved partition (the 100MB one that’s created by default).

Doing the following things helped to resolve the problem and now my backups to a remote NAS (SS4200-E).

1. Run Command Prompt in administrator mode (hit Start, type cmd.exe, right-click and select Run as administrator)
2. In Command Prompt type fsutil usn queryjournal F:
3. If it does not say that journal is disabled then type fsutil usn deletejournal /D F:
4. Retry backup. It should work as it is supposed to.

This is assuming that you have assigned letter F: to System Reserved partition. If not, you have to assign a letter to it.

1. Hit Start, right-click on Computer and select Manage. 
2. In Computer Management -> Storage select Disk Management.
3. Right-click on partition named System Reserved and choose Change Drive Letter And Paths…
4. Hit Add… button and choose a letter to assign. And hit OK.

Then do the disabling of USN Journal again.

Source for this post is here.