Trend Micro Norton Symantec McAfee

Hijackthis is a free utility which quickly scans your Windows computer to find settings that may have been changed by spyware, malware or other unwanted programs. HijackThis creates a report, or log file, with the results of the scan.
Home & Home Office Security Reports

This report will give you, the home and home office user, an overview of Internet security concerns that may affect you and show you what you can do to protect your valuable data.
Mcafee Free Scan

Based on the Award-Winning McAfee VirusScan Engine FreeScan is a FREE service that helps you detect thousands of viruses on your computer. Based on the award-winning McAfee VirusScan engine, FreeScan searches for viruses, including the latest known "in the wild" viruses, and displays a detailed list of any infected files.
Housecall Free Scan

HouseCall is a FREE Web-based tool designed to scan your PC for a wide range of Internet security threats including viruses, worms, Trojans, and spyware. It also detects system vulnerabilities and provides a link so you can easily download missing security patches. After each scan, HouseCall delivers a detailed report, which identifies security threats detected on your computer.
Virus & Threat Removal Tools

Symantec now offers a Spyware & Virus Removal service. Sit back and watch while a Symantec expert scans and clears your PC of spyware and viruses. This is a fee based service.
Mcafee Wifi Scan

Wi-FiScan determines the security level of your wireless network connection. If security risks are found, McAfee will suggest security measures you can put in place to reduce your risk.
Other Excellent Free Resources
Free for home use antivirus.
Grissoft AVG
Free for home use antivirus.
Lavasoft ADAWARE
Free spyware removal tool.
Open Office
Open source free/donation home office productivity suite, MS Word and Excel compatible.
  Microsoft Windows Defender
Free spyware prevention and removal tool.