AVG Free for Windows is a free anti-virus protection tool developed by Grisoft for home use.

• Rapid virus database updates for the lifetime of the product
• Easy of use
• No system slow down
• Automatic update functionality
• The AVG Resident Shield, which provides real-time protection as files are opened and programs are run
• The AVG E-mail Scanner, which protects your e-mail
• The AVG On-Demand Scanner, which allows you to perform scheduled and manual tests
• The AVG Virus Vault for safe isolation and handling of infected files
• And most of all ... great customer satisfaction!
  

We here at Kleebz.com have been using this for over a year and find it to work as well as if not better than many of the major programs.  It does not have all the bells and whistles but that means less memory usage.

Click on the link on the left side of the site to download