How do I know my computer is infected?

Posted by kent on January 12th, 2010

The following post in our Reader Question series is an actual user submitted question.

Q: How do I know my computer is infected?

A: There are many signs that can point to a possible infection: slow PC performance, numerous unwanted pop-ups, virus notifications from software you never installed, or phantom emails sent from your computer without your notice. Or you could be experiencing none of these things and still have an infected PC. Successful viruses infect your computer without giving themselves away.

You can find out if your computer has a virus by using a free virus scan. There are free virus scanners offered by a number of vendors that we reviewed such as McAfee and Norton, among others (click any of the prior links to access the virus scanners). If you get a clean bill of health from one or more of these virus scanners, you can breathe a sigh of relief. When you're done doing that, go and get yourself some real protection with a well-rated Internet security software suite. Free virus scanners (from reputable companies, like the ones we review) are great for a quick diagnosis, but they won't proactively protect you from keyloggers, trojans, or other malware.