Anti-Virus software
http://www.pandasoftware.com/
Provider of integrated security solutions to protect your PC from viruses, spyware, hackers, spam and other Internet threats.
http://www.mcafee.com/
McAfee, Inc, the leader in intrusion prevention and security risk management, proactively secures systems, and networks, worldwide.
http://www.symantec.com/
Symantec is the global leader in information security and availability, helping customers secure and manage their data.
http://www.grisoft.com/
Founded in 1991, with corporate offices in Europe and the USA, Grisoft is focused on developing software solutions that provide protection from computer viruses. Grisoft's primary focus is to deliver the most comprehensive and proactive protection available on the market.
http://www.free-av.com/
Free download of leading antivirus software package. Well suited for Windows XP, 2000, NT, 98, ME. It detects over 250000 viruses. Includes a resident monitor and a desktop program. Available in English and German, complete, easy to use plus virus removal. Regularly updated.