When trying to install Microsoft Dynamics CRM 2011 Update Rollup 6 or higher you get the following error:
Action Microsoft.Crm.UpdateWrapper.MspInstallAction failed. The upgrade cannot be installed by the Windows Installer service because the program to be upgraded may be missing, or the upgrade may update a different version of the program. Verify that the program to be upgrade exists on your computer and that you have the correct upgrade
The full install packages (slipstreams) for version 5.0.9689.1985, were re-released. This was the install packages that included Update Rollup 6. Due to this re-release the old install packages are no longer valid for future Update Rollups.
To resolve this issue you will need to uninstall the current Dynamics CRM Server, Client, E-mail Router or any other component you may have installed using those slipstream packages. Then you will need to reinstall with the new packages that are available on the Microsoft Download Site.
If you are on Update Rollup 5 or an earlier version of Dynamics CRM 2011 you will not see this issue updating to the re-released Update Rollup 6 patch.
Update Rollup 6, install, MSPInstallAction,