If your computer is running Windows 8, you already have antivirus software. Windows 8 includes Windows Defender, which helps protect you from viruses, spyware, and other malicious software.
If Windows Defender is turned off and you don’t have another antivirus program installed (or your other antivirus program is not working), you will see a warning in the notification area on your taskbar.
Windows 7 includes spyware protection, but to protect against viruses you can download Microsoft Security Essentials for free.
To find out if you already have antivirus software:
If Windows can detect your antivirus software, it's listed under Virus protection.
Windows doesn't detect all antivirus software, and some antivirus software doesn't report its status to Windows. If your antivirus software isn't displayed in Action Center and you're not sure how to find it, try any of the following:
Windows Vista does not include virus protection. To protect against viruses, you can download Microsoft Security Essentials for free.
The status of your antivirus software is typically displayed in Windows Security Center.
If Windows can detect your antivirus software, it will be listed under Virus protection.
Windows does not detect all antivirus software, and some antivirus software doesn't report its status to Windows. If your antivirus software is not displayed in Windows Security Center and you're not sure how to find it, try any of the following:
Click the security icon on the taskbar, or click Start, select Control Panel, and then double-click Security Center.
On April 8, 2014, Microsoft will end support for Windows XP. This means that after April 8, there will be no new security updates available through automatic updating for computers that are still running Windows XP.
Also on this date, Microsoft will stop providing Microsoft Security Essentials for download on Windows XP. (If you already have Microsoft Security Essentials installed, you will continue to receive antimalware signature updates for a limited time, but this does not mean that your PC will be secure because Microsoft will no longer provide security updates to protect it.)
For more information, see Support is ending soon.
Get more information about upgrading to Windows 7 and Windows 8.
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