Some antispyware software are free, though sometimes the paid versions have more features available such as removing spyware automatically rather than requiring a manual system scan. Most antispyware will find every piece of spyware on your PC, since they rely on a database, but a few stubborn spyware may slip through the cracks.

Some types of spyware are notoriously difficult to remove. They could make changes to your Windows files that enable them to hide from scanners. On occasion, you might need to delete these files manually to be sure they're completely gone.

Needless to say, this should be done only by skilled users. Deleting the wrong files may damage your programs and even your Windows operating system.

Once the spyware has been removed from your PC, you should run a scan on a regular basis to keep it safe. You can do this manually or use a program that automatically scans on a schedule is up to you.

And of course, always be knowledgeable of the risks before you accept any offers of "free" software on the Internet. And beware of online security attacks. You never know what its going to really cost you in the end.