One other thing you may try is to run the Windows One Care Free Scan which may clear some problems in the registry. It's worth a try.
Go to Windows Live Onecare Free Scan (using Internet Explorer only)
It will say "Get a free PC safety scan"http://safety.live.com/site/en-us/default.htm
Make sure you click "Full Service Scan"
in the middle of the page and not the "Try It Now Free" on the right side.
Allow it to download the Active X components.
Choose "Complete Scan" in the window that opens
Do not click on anything else that offers you a free trial or to sign up if you live in the US.
Allow it to scan - it may take quite, maybe two hours or so depending on how big your hard drive is and how fragmented your registry and drive are.
If that does not work, take advantage of the fact that Microsoft's policy is to provide free support for problems involving critical updates.
Microsoft Security Product Support Policy
Technical support is available from Microsoft Product Support
Services at 1-866-PC SAFETY (1-866-727-2338). There is no charge for support calls associated with security updates.
International customers can get support from their local Microsoft
subsidiaries. Phone numbers for international support can be found
You can access Microsoft from the Windows and Microsoft Update pages as well. When the Update page opens click "Get Help And Support" on the left side of the page.