The Microsoft Dynamics CRM Sustained Engineering (SE) team have been hard at work to get the UR4 release to us all so please take alook at the CRM Team blog for further details. http://blogs.msdn.com/b/crm/archive/2011/09/22/update-rollup-4-for-microsoft-dynamics-crm-2011.aspx
- Microsoft Download Center: http://www.microsoft.com/download/en/details.aspx?id=27554
- Microsoft Knowledge Base Article: http://support.microsoft.com/kb/2556167
- Microsoft Update: http://catalog.update.microsoft.com/v7/site/Search.aspx?q=2556167
You cannot remove Update Rollup 4.
Specific database updates are applied in Update Rollup 4 that will not let you uninstall Update Rollup 4. You should back up your databases before you install this update.