Oh, this one brings back miserable memories. We had a batch of TabletPC 2005 systems our VAR was inexplicably and unexepctedly jamming MediaCenter components onto but without all of the MCE menus so were unaware of the the silly dancers and other stuff on
the systems but it was enough components to trigger the MCE HotFixes at WindowsUpdate.
Seems you're aware of and want MCE so sharing this registry edit is appropriate, navigate to the MediaCenter Ident (RegSZ) key and verify it isn't already "3" and retry the hotfix.
It is recommended to reset the Ident key back to your original value but not 100% necessary, system anomalies may or may not occur and no one seems too sure or interested anymore in determining the results.
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