3 Errors at startup

This Hp laptop reasonably new (6 months) has developed 3 errors at startup. Vista premium. Apparently the owner, a novice, has been doing quite a bit if playing around itin its system.
c:\windows\system32\nvsvc.dll
c:\windows\system32\nvCpl.dii
c:\windows\system32\nvMcTray.dll
nv gives it away as an nvidea fault.
I have not seen the laptop so i know little about it.
I have read that it is sometimes caused by nvidea drivers going on an ati system. (hard to beleive)
Question is how to stop the errors.
Nothing else seems to have a problam.