Windows Updates continuously failing. (0x80073712)

@dmex: Tried it. Same error.

@sidney1st: Thanks, I'll try that.

try running error checking and let it fix and recover all errors

dude, that has nothing todo with Windows Updates.

Me and a guy from MS Support has tried to search for the problem. According to MS this problem only happens to machines with antivirus software. The problem seems to be permissions-related and so far the only solution has been to reinstall the OS or use a recovery disc.

This is what we have done:
1. Search all disks for errors.
2. Take ownership of C:
3. Enable all permissions for the Sys Admin and User Admin accounts on C:
4. Take ownership of the registry (resulted in crash of the Reg editor)

This is what i'm going to try
5. Uninstall Avast antivirus and try update
6. Backup system, repair Vista and try update
7. Total reinstallation

8. Report to MS Support