I have exactly same problem and have been searching for an answer few days now... i'm actually trying to make system image, but it is similar...
And i know exactly what is the problem - I/O errors, one of my disks in Intel Raid 0 is having trouble, but windows is still working, chkdsk /r repaired few errors that showed up, but every time i try to create system image, i get the same error as thread's author
The problem is that Windows Backup cannot handle occasional I/O errors, is there any solution to that? I Want to backup my system as it is, even with small I/O glitches, since it's better to have such backup than no backup
any idea how to force windows backup to ignore occasional I/O errors?
chkdsk seems to not find them anymore. (it fixed few, but if i run it now it cannot find anything new)
i have also tried sfc /scannow
But disk has problems for sure, if i mark the disk in the raid as Normal from Error, it goes back to error after few minutes and i see I/O errors in the event log. but windows is fine, programs are fine, games are fine, documents are fine, i'm sure that it is just small part of the disk that is affected.... how to force windows to ignore it just for the backup purposes?