You cannot install some earlier updates if an exclusive update is offered on the Microsoft Windows Update Web site or on the Microsoft Update Web site

Consider the following scenario:

• You visit one of the following Microsoft Web sites and scan for available updates:
  • Microsoft Windows Update
  • Microsoft Update
• After the scan has completed, you are offered an exclusive update that must be installed separately from other updates.
• You do not install the exclusive update.

In this scenario, some earlier updates that are required on the computer may not be offered. Additionally, if you run the Microsoft Baseline Security Analyzer (MBSA) tool, some security updates may be missing.

The Windows Update Web site and the Microsoft Update Web site list exclusive updates first. The exclusive updates may contain security updates that were released earlier. If you do not install the exclusive update, the computer may still require updates that are currently being hidden or superseded by the exclusive update.

To resolve this issue, hide the exclusive update, and then scan for the updates that were previously hidden or superseded. To do this, follow these steps:

1. Hide the exclusive update. To do this, follow these steps:
   1. Start Microsoft Internet Explorer.
   2. On the Tools menu, click Windows Update.
   3. Click Custom.
   4. Click Review and install updates.
   5. In the first section of the Updates Web page, expand the exclusive update.
   6. Click to select the Don't show this update again check box.
      
      Note If the Don't show this update again check box is not available, click to clear the check box that is to the left of the superseding update. Then, click to select the Don't show this update again check box.
   7. Click Review and Install updates.
2. Scan for updates again. To do this, follow these steps:
   1. Start Internet Explorer.
   2. On the Tools menu, click Windows Update.
   3. A list of the updates that are superseded by the exclusive update appears. Click to select the updates that you want to install, and then click Review and Install updates.
   4. Click Install Updates, and then follow any additional instructions that appear.

An update may be an exclusive update if the Windows Update Web site or the Microsoft Update Web site uses one of the following category descriptions:

• High-priority updates
  The updates that are listed in this category may have system-wide effects or address more than one problem. A high-priority update must be installed separately from other updates. We recommend that you install the high-priority update and then return to the Windows Update or Microsoft Update home page to see whether the computer requires other high-priority updates.
• These updates must be installed separately
  The updates that are listed in this category may have system-wide effects or address more than one problem. We recommend that you install any updates that are listed now and then check again. Start by checking the Windows Update or the Microsoft Update home page for remaining updates.

For more information about this issue, click the following article number to view the article in the Microsoft Knowledge Base: For more information about MBSA, click the following article number to view the article in the Microsoft Knowledge Base: