Many virus and spyware programs affect Windows' ability to connect to common security websites, either to update existing antivirus/antispyware products or to download a new product. The links below allow you to download the current versions of these free best-in-class products from this website, so you should be able to download them even if your computer is infected with malware that prevents downloads from the vendors' websites.

AVIRA and AVG are both very good antivirus programs. Choose either one.

Windows Defender is Microsoft's antispyware program, and is designed to work seamlessly with Windows XP or Vista.