A exclusive update is an update that must be installed by itself. IOW, if you pick it, it HAS to be the only one you pick. Also, there is an option to ignore exclusive if you are using the Update Management Wizard. It is on the second page of the wizard. If you tell it to, it will ignore exclusive updates.
It was the only update I picked to install, but it did not install. I did not choose to ignore exclusive. Here is the task:
Purpose: Configuration Management
Submitted By: DOMAIN\Administrator
Created: 5/18/2010 3:42:46 PM
Task ID: N/A
Schedule: Daily at 3:43 PM and starts on 5/18/2010 and reoccurs with no end date.
Export Options: The results will not be exported.
Email Options: The results will be emailed to (firstname.lastname@example.org).
Reboot before: No
Reboot before only if required by Windows Update: Yes
Maximum wait time on pre-reboot (in minutes): 5
Reboot after: No
Message: On behalf of user domain\administrator, a reboot request was made for the installation of updates/software.
Force downloads: No
Force installs: No
Use Microsoft Update Catalog: No
Include Only Approved: Yes
Approved Only Option: Any approved update
Dont include superseded: No
Install exclusive update only if found: No
Planning Mode: No
Reboot After (Only if require by Windows Update): Yes
Reboot After (Only if updates succeed): No
Do not include exclusive updates: Yes
Rule: KB article equals '925876'