[nogbad]

I took on helping a colleague sort out his infected laptop. I ran spyware doctor, trojan remover and then avast. It was looking a lot better until I did a boot time scan with avast. it found infections in all the system 32 files.
Now heres where I did something really stupid Doh!!!!
I clicked on move all to chest, which it did.

Now when i start up the computer I get a log on screen. as soon as i log on, the desktop flashes up briefly then i get saving settings and end up back at the log on screen. it wont let me log in as administrator and it behaves the same way in safe mode.

i kind of suspect that I shouldn't have moved all those files, but as i cant log on, dont know how to move them back.

Any help would be greatly appreciated.
the PC's running xp home which didnt come with an xp cd. i do have an xp pro cd.

thanks