Fresh install of Windows once a year or so is what I do to keep everything run zip zap.

When I mean fresh install, i mean installation from a the retail CD. Recovery CDs are always full of crappy ass bulkware that slows down PCs

use only ONE spyware and anti-virus program. Do not use NORTON or MaCAFFE, they suck ass.

I use AVAST, and that shit is free.