If a program looks too good to be true, it probably is

The number one source of spyware infection is free software programs you download from the Internet. Pay careful attention to what you are downloading and know what other programs it may bring into your PC along with the original file. Unfortunately, even if you've done your homework (and yes, that means reading those pesky User License Agreements prior to installation), some spies might still slip through unnoticed, even with good firewall protection.

Practice safe surfing

Avoid websites that offer unscrupulous content such as pirated software or adult material. These sites are notorious for spreading spyware.

Secure your browser

Set your browser's security settings high enough (Medium on Internet Explorer) to protect yourself from "drive-by downloads," or automatic installation of unwanted programs. In addition, make sure that you are only downloading programs from reputable sites, and that you've checked out reviews by other users before installation.

Delete spam

Email is a common delivery vehicle for spyware. Delete messages from unknown senders and use caution with any email containing an attachment, even if it's from someone you know. Even reviewing an email in the preview pane can initiate spyware program downloads, so it is recommended that you turn off that option.

Be wary of cookies

Cookies may add convenience during your browsing sessions, however they can also track your activities while online and relay that information back to third parties without your knowledge. The outbound communication caused by cookies also slows your internet connection and can negatively affect you online experience.

Beware of peer-to-peer file sharing services

There are two issues with P2P networks (like Kazaa, Morpheus etc). One, P2P network clients often load spyware onto your PC when you sign up for their service. There are P2P networks that come in a light or alternate version, free of spyware. Two, the files you may be swapping and sharing (photos, music, videos or games) may contain spyware.

Run anti-spyware software

Detecting and removing spyware is a difficult business. Even if you think you've successfully removed a piece of spyware manually, a remaining tickler file can trigger a complete reinstallation at start up of the spyware program you worked so hard to delete. Effective anti-spyware software provides users with regular updates to combat the latest spyware variations. Run scheduled or manual scans, and make sure you select any proactive monitoring options the software may have. Also, fortify your defenses with anti-virus and firewall protection.