Got a popup blocker? Sometimes spyware will install popup blockers (in IE, go to view --> toolbars --> and see what's there). But popups are not the only form, that's more adware. You may have tracking cookies, malware, loggers, worms, trojans....the list goes on and on, and they'll all affect your speed and overall PC performance. The only way to really know if you've got them is to run a scan to find them. Why not do it? It's easy....