Cant get past the welcome screen with xp

Hello,

I started to get the anti virus xp pro on my main computer, i did try to eliminate it , however on reboot it seemed to be eracing some of my files, at 1st i did think i got rid of it, but now it automaticly logs me off putting me back to the welcome screen. i cant get in no matter what i do. any help will be .

i did attempt to boot it in safe mode and suffer the same problem

appreciated