My virus checker quarantined a virus that attacked my windows sign-in (the log in screen that takes my user name and password)but it also destroyed the software that windows uses to sign me in so I cant get into windows xp (this happened on a different computer in the same household). I can't log in with my username and password anymore and it won't allow a guest log in either. I tried safe mode and restore but it also requires to log in as adminstrator but it doesnt accept my password anymore - help1 person needs an answerI do too