Hello forumers, I upgraded my windows xp desktop from service pack 2 to service pack 3. It's because I wanted to play Gta 4 and thus I upgraded it. My com became laggy as a result and so the next day I decided to system restore to an earlier time before I installed sp3. I tried system restore a few times, and It says it failed to restore. And so I tried uninstalling sp3 and installed sp2 back but it says sp3 fails to uninstall. So I tried system restoring back, but this time it come out an error which says ' autochk.exe was not found ' and it just restarted back before I could even click my user to access windows. I did search on google about this problem and it says to use regedit.exe, but most of the guides are a few years old and they wanted to use floppy disk instead. I don't have one and I tried to use thumbdrive but it didn't work. I also did try safe mode and Using Last Known Good Configuration but neither works. Anyone could help me? It will be much appreciated. Regards, BlueFirzen.