Spyware is a huge problem right up there with computer viruses. But how do you know if you've got spyware on your computer? There are several warning signs that you can look for.

Here's the top eight signs that you may have spyware running on your computer:

Popup Windows:

Popup windows are a common indicator of spyware. If you see popups even when you aren't using the internet, you need to start a spyware scan immediately.

Ineffective Popup Blocker:

Most web browsers now have built in popup blockers. Some spyware programs are able to get around popoup blockers or even disable them.

Strange Desktop Icons:

New desktop icons for software that you didn't install is a surefire sign that spyware programs have been installed on your computer.

Slow Computer:

If your computer has suddenly gotten slower and slower you may have an infection. Hidden spyware programs run in the background without your knowledge. These programs use up system resources such as RAM and CPU cycles slowing your computer down.

Firewall Warning:

Everyone should be running firewall software these days. If your firewall is suddenly giving you lots of warning signs and popups, it could be spyware on your computer trying to access the internet.

Different Home Page:

Many programs will change your browsers homepage to a malicious one or one filled with ads. You may change it back and find out that it's changed again the next time you start up your web browser.

Browser Toolbars:

New browser toolbars are another common indicator that spyware is running on your PC. These are easy to notice as they usually sit at the top or bottom of your web browser screen.