Can't login

I have xp pro

I think I had a virus, from a downloaded email, I got a BSOD. So I restarted to run the clean up but i could not get any tools to work, in regular mode or safe mode. I downloaded a new anitvirus and that worked, it found only three files that infected. The only way to stop those files from coming back was to delete them.

Now I can not login. I tried to boot from the boot disk, no luck. I can "see" the hard drive on my network, and I have replaced all the files in the I386 folder, but I am not allowed to access the winnt folder. I can copy to the hard drive but I can not run any programs.

I am stuck, any help would be appricated. I have no logs, sorry.

Thank you,
Mandy