Don't forget about using a firewall app such as ZoneAlarm and a spyware app such as Ad-Aware.
As you download more and more Windows, Office, IE, and other updates, you must realize these
may allocate more of your system's memory; you should buy more more memory or at least increase
virtual memory. You should also remove/close unnecesssary or unused applets in your sys tray
(bottom right corner) Also, you can uninstall add-on search bars that soemtimes get installed free
with other software.
Don't forget about cleanup in IE viaTools > Internet Options. Follow this with Start > All Programs >
Accessories > System Tools > Disk Cleanup.
Also, see if you have multiple pop-up blockers installed.
Uninstall sofwtare you don't need; some auto-start polling/listening applets
under windows task manager.
There should be some shareware tools out there to analyze yor system and or help cleanup