PC Malware Tips
If you own a computer that uses a Microsoft operating system, you will be plagued by malware. In addition to needing an anti-virus program, you'll need to deal with adware and spyware.
You could turn your back on 'Windows' and go with Linux, or get a Mac (which also uses a variant of the more-secure Unix OS). Otherwise, here are some suggestions:
If you think you have a deceptive (spyware or adware) application on your computer, or if you just want to check to be certain, there are a number of programs that can help you. Spybot Search and Destroy, LavaSoft's Ad-aware, and CWShredder are commonly used. These programs can remove the most common malicious applications, though you may need to try more than one, and having the latest versions is important.
While security from viruses, spyware, adware, worms, etc on the Mac is far less of an issue than on computers running Microsoft operating systems, Mac users are NOT immune to attacks.
Mac OS X Safari users can protect themselves by disabling the "Open safe files after downloading" option from within Safari. Of course, all users should be cautious when surfing the Web, accepting files only from vendors and Web sites that they know and trust.
For more detailed security precautions, see Apple's Safety tips for handling email attachments and content downloaded from the Internet.
For info on the relative vulnerability of Windows- vs. Unix based-systems, see Mac OSX safe as houses not Windows.