Win XP home edition

Here's the problem:

Win Updates used to update just fine, reboot, install, etc.
Until about 1-2 months ago. I don't remember any specific event or anything happening. It just refused to install all the updates it downloads. It would either freeze during install, or not install at all on shutdown.

Here's what i have tried:

1- tried to manually download and install, it just freezes once it starts to install. and then it disappears.
2- ran Microsoft Baseline Security Analyzer, it found the updates I needed were missing, but no other problems.
3- tried to restart Crptographic service, because the error code fix on Microsofts website says it may need to be restarted.
4- tried to run Windows Update Fix from wiki.castlecops.com/Windows_Update_Fix. it was unable to rename catroot2.
5- tried to follow microsofts fix and manually rename catroot2, it says the file or folder is in use. (nothing else was running)
6- tried to run dial-a-fix fromwiki.lunarsoft.net/wiki/Dial-a-fix but it also did not work.
7-after each step tried to install an update, but it did not work.

Please help. I think it is beginning to affect my computers performance. Thanks!