How do i remove the tidserv.h virus?

i just recently bought a used compaq notebook with windows xp last week...the man i bought it from had cleaned it and reloaded xp..everything ran fine until a few days ago...i believe i have the tidserv.h virus..my computer is down...it says the atapi.sys is corrupted. it wont let me run my operating system cd for windows xp...it says it doesnt find a hard drive. i tried my driver recovery cd..no luck..i know my hard drive is there cause windows sometime opens, then i get an error blue page and it shuts down. tried opening in safe mode..it wont ...tried loading a virus cleaner..it wont load...how do i get into my laptop to remove the virus?