In my case, I had a recent full re-structure of my 2008 PC box,
to an H77 based motherboard.
I bought a new external 2Tb Hard Drive.
After a pristine full re-installation of Windows 7 Professional, Windows
Backups initially worked;
however, once I connected the external 2 Tb HD and installed it's proprietary
(extra) software, AND re-installed my licensed KIS 2012,
I received the same error message after my weekly Windows Backup - 0x81000001.
In my case I fixed this by -
- disabling KIS 2012 and disconnecting from the Internet, and rebooting, and
- switching off the 'Turbo Files' and other extra programs that came with the external HD, and
THEN my backup worked fine !
It seems that changes when new hardware and/or new software are installed,
may affect the internal O/S checking of the validity of backups. The failure seems to be in the
System Image checking.
- hence the warnings elsewhere to consider returning to simpler A/V protection, etc.
However, the Error Code is not particularly helpful in pin-pointing the precise cause.