Microsoft offers free antivirus protection software for Windows

Do you know that Microsoft now offers a free, quality antivirus application for Windows? Last year, Microsoft released Windows Security Essentials. This is Microsoft's free and lightweight antivirus and antimalware product that protects Windows XP, Vista and Windows 7 from malware. Best of all, unlike the other free products available, there are never any additional sales or excessive pop-ups trying to convince you to pay for a superior end product. This is usually the case with products like AVG Free and other "free" malware products. This combined with the built-in firewall in Windows Vista and Windows 7 provides all the protection you would need for your Windows computer. In Windows XP, the firewall is less configurable but also provides adequate protection.

Earlier this year, Microsoft released the second version, Security Essentials 2011, which offers better protection and an updated user interface.

Windows Security Essentials is updated daily and provides a scheduler with a predetermined schedule to scan your computer weekly. The interface provides four tabs. The Home tab provides a quick view of your computer's protection status and offers the option to perform a manual scan.
The Update tab provides the status of virus signature updates and the option to manually update the signatures.
The History tab, as the name implies, provides a historical view of any malware detected, cleaned, or quarantined. mindmap

The Settings tab provides access to application settings, allowing you to modify the scan program, what actions to take when malware, files, file types, and folders are detected to exclude from scans, and more.
You can also change the level of engagement for Microsoft SpyNet. This is a feedback feature that sends anonymous data to Microsoft about the various malware that tries to infect your computer. This multi-source feature enables Microsoft's faster and better response to virus outbreaks, which is ultimately best for you and the user community. There are three levels you can choose from:

You can choose not to participate.
Basic membership: the default settings, or
Advanced membership.
The basic membership sends data on the origin of the software, the actions that you apply or that Security Essentials applies and whether those actions were successful or not.

Advanced membership submits additional information such as the location of the software, file names, how the software works, and how it has impacted your computer.

This is the option that I generally choose because I think it improves the software, which is ultimately good for me. For the paranoid you can choose not to participate at all.