Autochk.exe not found - Skipping autocheck?

I am running windows xp home and when I was installing some software, I thought it froze so I ended the process which it must of been installing something into the registry because now I can't turn on the computer. It keeps saying "Autochk.exe not found - Skipping auto check." then it just restarts and keeps doing that same thing. I tried to load last working configuration and it didn't work. I also can't boot into safe mode. I used ptedit and checked and the partion is not hidden. I thought about copying an autochk.exe from my friend's computer and putting it in windows/system32 but I'm not sure. Please help.