
if you mean wiping your computer back to factory settings, then follow below.
if you have recovery CDs then you can use them or you might have a Recovery Partition you can use.
or if you have made a mirror image you can use that.
Dont know if you have Recovery Partition? when you resartt your pc right at the start look near bottom of screen and you should see something like press F10 to enter Recovery
or something on them lines.
Note: make sure you backup all your data as this will be deleted