Excuse the boilerplate ( hattip: SWI forums )--
These are some recommendations that will significantly decrease the chances that you will have problems with malware in the future:
1) Regularly go to http://windowsupdate.microsoft.com and download all the "critical updates" for Windows, including the latest version of Internet Explorer. This can patch many of the security holes through which attackers can gain access to your computer. You should also turn on the Windows automatic update feature.
2) In order to protect yourself against spyware, you should consider installing and running the following free programs:
Ad-Aware SE
A tutorial on using Ad-Aware to remove spyware from your computer may be found here.
Spybot-Search & Destroy
A tutorial on using Spybot to remove spyware from your computer may be found here. Please also remember to enable Spybot's "Immunize" and "TeaTimer" features.
Microsoft Anti-Spyware
SpywareBlaster
A tutorial on using SpywareBlaster to prevent spyware from ever installing on your computer may be found here.
SpywareGuard
A tutorial on using SpywareGuard for realtime protection against spyware and hijackers may be found here.
Keeping these programs up-to-date and running them regularly can prevent a great deal of spyware hassle.
3) Please consider using an alternate browser. Mozilla's Firefox browser is fantastic; it is much more secure than Internet Explorer, immune to almost all known browser hijackers, and also has the best built-in popup blocker (as an added benefit!) that I have ever seen. If you are interested, Firefox may be downloaded from here:
http://www.mozilla.org/products/firefox/
4) Also make sure to run your antivirus software regularly, and to keep it up-to-date.
5) Finally, consider maintaining a firewall. A good free firewall is ZoneAlarm.
A tutorial on understanding and using firewalls may be found here.
Please also read Tony Klein's excellent article: So how did I get infected in the first place?
Things you need(all FREE)
Anti-Virus
AVG
Run a hardware firewall-- with today's LAN's, it's easy. You need a hardware firewall.
Dropping out of cut n' paste, lurk & link mode for a moment?
Some online scanners, like Ewido, also scan for spyware, and sometimes find what the more popular Ad-Aware or Spybot seem to miss.
I've used AVG on the home machines for a couple of years, but after a trial of Avast! found one .dll file AVG and all the online scans missed, I switched the main PC to Avast!