All the details at http://www.microsoft.com/technet/security/advisory/975497.mspx and read the KB http://support.microsoft.com/kb/975497
To fix this problem automatically, click the Fix this problem link related to Disabling or Enabling the bulletin. Then click Run in the File Download dialog box, and follow the steps in this wizard.
Note This wizard may be in English only; however, the automatic fix also works for other language versions of Windows.
Note If you are not on the computer that has the problem, you can save the automatic fix to a flash drive or to a CD, and then you can run it on the computer that has the problem.