curious why this is even in graphics as it has nothing to do with graphics and everythign to do with either A. cpu or B. OS
technicall both are correct that being dipanker and mouse monkey.
the question is do you want to know which os you are running in which case do dip's advise
if looking to upgrade the os and trying to find out which one you can run 32 bit or 64 follow monkey's advised
I took the assumption that the OP wants to know which graphic driver to download.