A freeware program (available for Windows 95 through Windows Vista) that monitors your computer for changes to your Windows registry (often a sign that a malicious program has infiltrated your system):
NOTE: Always scan downloaded programs with your computer’s security software before installing on your computer-- better safe than sorry!
NOTE NO. 2: Consider saving downloaded programs to a MY DOWNLOADS or NEEDS VIRUS CHECK folder. Then get in the habit of checking whatever’s still in that folder before installing any program in that folder. That way you won’t forget to virus check before installing a new download!