Customer has installed a Hyper-V Cluster. The host os is Windows Server 2008 R2 with SP1. When he runs cluster validation wizard, the wizard shows lots of missing updates, however those updates are already in SP1 package. When he checks for updates from Windows Update, no new updates are detected.

He is unable to install the "missing update" saying they are already on the system. This is usually seen after Add Node.

This problem does not happen when hosts are installed with stock Windows Server 2008 R2 and applied SP1 later.


Root Cause:

Validate compares the hotfix numbers, not the binary versions. Because hotfixes and SP's are cumulative, there can be cases where you install a cumulative hotfix and Validate gives a false positive.

Repro steps:

1. Node1 = Hotfix 1, then SP1

2. Node2 = Hotfix 1, then SP1

3. Add Node3 = SP1, now Node1 = Node2 = Node3

4. Validate reports Hotfix1 is missing on Node3



On Node3, uninstall SP, install hotfixes then apply SP again. Actually you can ignore this Validate warning!