how can i remove corrupt files from the program C?

if you have a recovery cd/dvd that comes with new laptops run the xp set up cd and it should give you an option to repair windows but it seems you may have a virus or ad/spyware.
run a virus scan and ad/spyware removel program first if this doesnt fix the issue then run the xp setup cd/dvd and choose the repair windows this should work as xp over writes system files as this is were i beleave the problem is (is there any other info about the name of the file/s that may be corrupt. hope this helps

jay
January 2008