Making your Windows OS more secure and improving your privacy online can become an awkward process given the number of things that can be done to improve it
TechSpot's Guide to Windows Security and Privacy
(updated) covers many of such known solutions for various popular applications which should make your system more secure and less prone to viruses. The guide has been prepared with Windows 2000 and XP users in mind, however a lot of the stuff contained here can be also applied to earlier versions of the OS, in addition to Internet Explorer and Outlook Express.
Read the complete guide here