after updating my windows xp home ed. with the sp-1 i started to get blue screens irql_not_less_or_equal. I loaded the driver verifier and after long ours testing drivers it came up with a blue screen noting portcls.sys as the reason of trouble. I have tried to replace the portcls.sys file in the drivers folder with a backed up version, but for some reason windows duplicates the recent file reinstalling it automatically.
How can I replace the faulty portcls.sys file, and can i download a new version somewhere. Microsoft does not have one.