1. Uninstall Microsoft Security EssentialsFor Windows XP:
- Click Start, click Run, type appwiz.cpl in the Run text box, and then click OK.
- Select Microsoft Security Essentials, and then click Uninstall.
- Restart the computer, and then go to the "Reinstall Microsoft Security Essentials" section.
- Click the Start button and in the Search programs and files text box, type Appwiz.cpl, and then press ENTER.
- Right-click Microsoft Security Essentials, and then click Uninstall.
- Restart the computer, and the go to the "Reinstall Microsoft Security Essentials" section.
2. Reinstall Microsoft Security Essentials
- Visit the following Microsoft website: http://windows.microsoft.com/en-US/windows/products/security-essentials
- Click Free* Download.
- Click Run, and then follow the on-screen prompts until the installation is complete.
- Restart the computer.
For support for Microsoft Security Essentials, visit: http://windows.microsoft.com/en-US/windows/products/security-essentials/support
Article ID: 2652423 - Last Review: Dec 6, 2011 - Revision: 1