antivirusXP08-computor wont boot now

I picked up this bug now not only can I not get rid off it I cant load up windows to do a virus removal, all I get is a black screen when windows loads this is what is on the screen system 32\hal.dll please reinstall a copy of this file I am running XP media center on a HP pavilion a1423w and the restore sytem to earlier time wont come up cuz windows wont load

Be prepared for the worse and work your way through here.