XP hangs up in "Welcome" screen

I was getting the "irql not less or equal" BSOD even in safe mode, so one of the IT guys here had me use recovery console to copy 5 files from the repair directory to the config directory (default, software, sam, security and system). The computer now boots in all modes until it gets to the "welcome" screen where it hangs. The hard drive light flashes but it's every second exactly, so doesn't seem to be doing anything useful. What should I do next?