Ok finally got some time to check this further. Attached pics show both the diskconfig for windows the drive im backing up is the 40gig showing as drive0 also can see the exact command line im typing. But still getting same problem.
I have put a different drive in and installed windows7 then removed the UAC crap. But once again same prob with cant open file ......
So yes i must be doing something totally stupid, or this is one very strange pc.