My laptop running Windows XP SP3 is configured to automatically install
updates. For quite some time now, Windows Update is trying to install an
update to .NET each time i shut down. Each time it fails.
Depending on something random (lunar phase? weekday?) that's either update
KB974417 or KB951847. Update for KB951847 always fails with error code
0x80070663, KB974417 fails with error code 0x645.
To me both updates look almost the same, so no idea why Windows Update
should chose one or the other or actually chose to install both.
No idea if this is related, but might well be the case: Some weeks ago
automatic update failed, because the hard drive was full to the last kilobyte
(hadn't done a clean up for a while). That time Windows couldn't shut down
and obviously also couldn't start up again after the hard reset I had to
execute. The system is fine now, except for this annoying behaviour with
Windows Update. I suspect there's still a corrupt file stored somewhere that
Windows Update refuses to download again.