1. USE Firefox. If you don't use the Internet very much, then maybe you don't understand a good deal concerning Firefox. All you need to comprehend is that it is a browser that performs VERY nicely and has excellent security protection.
2. DO NOT USE Microsoft Internet Explorer. Internet Explorer is similar to Swiss cheese. It seems to have an endless supply of security holes. Microsoft is ceaselessly sending out patches to fix all the flaws in the Internet Explorer 6.X and prior versions of the browser. Even though it can be "secured" by adding to thesecurity it may give away much of its functionality when set to highest security when specific exploitable features are turned off.
3. Use a software or hardware firewall (not only Windows XP Service Pack 2's firewall). This may be thought to be expensive and difficult to do but it is not. If you use a DSL or broadband cable connection your Internet Service Provider (ISP) may have issued you a DSL/Cable router that has a a firewall included with it. All you need to do is switch it on. This may force you to spend a few minutes to read the instructions.
If your ISP did not deliver you a DSL or Cable broadband router that includes a firewall you can shell out anywhere from $20 -$60 (or occasionally even cheaper when it includes a mail-in rebate) to get a router. If you use DSL you would require a DSL router. If you use Cable broadband ISP you would need a Cable Router. Brands such as Linksys have already built in firewalls and a feature known as NAT, Network Address Translation, which is extremely effective because it hides your actual IP address from the Internet. All routers are sold with directions on how to hook them up. If you desire to maintain you computer security free, merely use a free software firewall.
4. Detect Spyware and Adware using free Anti-spyware, anti-adware software. Lavasoft's Adaware and Spybot Search & Destroy are two superb methods of restoring your system for free. Majorgeeks.com is a favorite and trustworthy freeware website that has these and several additional outstanding spyware/adware cleaning and malware preventing software (including free downloadable firewalls).
The best approach is to use ALL of the options. Remaining proactive by surfing using a suitable browser and obtaining a firewall is critical, but it likewise helps to beware of other good anti-adware/spyware applications. If you get hit with a genuinely foul bit of malware that can not be cleaned using Adaware or Spybot, dig up yourself a geek. There are numerous big forums on the Internet committed to accomplishing nothing but to detect spyware and adware and remove them and other malware. In all likelihood if your computer is contaminated with it, hundreds of others prior to you have been contaminated and have previously figured out how to get rid of the malware.