I have a multi-file RAR archive with an SFV file which I have checked several times using a couple of different programs (QuickSFV and SFV Checker) and both keep changing their report each time I run them, computing different checksums for each file on each iteration.
Can anyone suggest why this may be, or how I might diagnose the cause?
Clarification: the issue is that the reported CRC for a file keeps changing each time I run it, where the file does not change. The context is an SFV file for a multi-file archive, and I'm computing the CRCs using QuickSFV/SFV Checker.
Update: I was able to extract the archive (which was originally failing because of a bad CRC, hence the need to check the SFV) by simply trying again and again until it worked, so the files were in fact valid and CRCs were randomly being computed incorrectly. I have no idea where the inconsistency is coming from though, and I'm interested to hear ideas.
Update: The computer had another spate of mini-freezes, when I restarted it complained about the 'header checksum' being incorrect and the file-system possibly being corrupt, and Windows did not boot. Further restarts eventually led to a 'no drive detected' message. I removed the side panels from my machine, unplugged the HD, blew on the slots/cables (I had a GameBoy, and old habits die hard), plugged it back in again and everything seems to be working once more (including resolving the original CRC inconsistencies). Perhaps the cable was a little loose, or some charge in the side-panels (somehow) was affecting the communication?