Uninstall the Windows defender and install am updated version. If it doesn't work, try this:
To resolve this problem, follow these steps:
1. Uninstall Windows Defender, and then reinstall Windows Defender. To do this, follow these steps:
1. Click Start, click Run, type appwiz.cpl, and then click OK.
2. Click Windows Defender, and then click Remove.
3. Follow the prompts to uninstall Windows Defender.
4. To reinstall Windows Defender, visit the following Microsoft Web site:
http://www.microsoft.com/athome/secu...yware/software (
http://www.microsoft.com/athome/secu...yware/software)
2. If this issue is not resolved after you complete step 1, uninstall
Windows Defender, use the Windows Installer CleanUp utility, and then
reinstall Windows Defender. To do this, follow these steps:
1. Click Start, click Run, type appwiz.cpl, and then click OK.
2. Click Windows Defender, and then click Remove.
3. Follow the prompts to uninstall Windows Defender.
4. To use the Windows Installer CleanUp utility, click the following article number to view the article in the
Microsoft Knowledge Base:
290301 (
http://support.microsoft.com/kb/290301/ ) Description of the Windows Installer CleanUp utility
5. To reinstall Windows Defender, visit the following Microsoft Web site:
http://www.microsoft.com/athome/secu...yware/software (
http://www.microsoft.com/athome/secu...yware/software)
3. If this issue is not resolved after you complete step 2, follow this step:
1. Click Start, click Run, type regsvr32 file name, and then click OK.
Note In this step, file name is a placeholder for the following files.
Repeat this procedure for the following files:
* wuapi.dll
* wuaueng.dll
* wucltui.dll
* wups.dll
* wuweb.dll
* atl.dll
* softpub.dll
* wintrust.dll
* initpki.dll
* mssip32.dll"
cheers ...