When windows update prompted me to install SP3, I went ahead. It downloaded fine, then inspected my system, then backed up files, then started to create a restore point, and hanged, after a while the systme was completely frozen, I had no other solution than power down the system.
Because it frooze during the restore point it looked like it had not actually started the update, and the system restarted fine in SP2 (System is Media Center XP SP2 with all updates). To be sure I did a restore with the restore point from the day before.
I though all was fine, and was prepared to leave SP3 alone, but then I found out that since the incident, svchost keeps running all the time at 50% of CPU. I tried to stop automatic update , no difference, I checked which program was running svchost, and it appears to be a long list of them. On top of that My media center is also Screwed up and cannot see the tuner anymore.
Obviously something from the aborted installation is making svchost run permanently. If I start in safe mode, svchost is not running permanently.
Given the original aborted install had the time to create the uninstall folder before crashing during the restore point, I tried to start in safe mode, and run the SP3 uninstall, but it hangs at inspecting your system.
Right now, I downloaded the ISO image of the SP3 CD, and burned a CD, I uninstalled my antivirus and Roxio, and cleaned up the registry from them, then I started in safe mode and launched the update from the CD, but so far it hangs at Inspectiong your configuration.............
Do I have anyway to cleanup whatever happenned as the result of this failed install ??
Observing the system behaviour since this incident, it appears that as soon as something triggers svchost, it hangs at 50% cpu for ever, and most of the time hangs the application that triggers it. Sometimes stopping the process will allow the application to continue. For example most installation program trigger svchost most of them hang as soon as svchost starts and hangs at 50%.
Anyone has an idea on what could cause svchost to hang ?
Well I found what was corrupted and messing up svchost. Here it is in case it can help someone.
It was the Catroot2 folder which was corrupted (in windows\system32). The good thing is you can actually rename or delete this folder and it will recreate itself clean (you do have to stop the Cryptographic service before doing that).
Since I removed the Catroot2 folder, everything is back to normal, svchost works like a charm and all the problems went away.