If you accidently installed a newer version over an existing older version of your Windows Home Server Add-in without first explicitly uninstalling the older version of that WHS Add-in or otherwise experience a corrupt Add-in Install & Remove facility- it may be necessary to manually remove that Add-in from your Windows Home Server.

Note: The below procedure described requires modifications to the Microsoft Windows registry. Please use extreme caution when you modify the registry.

To manually uninstall a Windows Home Server Add-In, follow these steps:
(Using Grid Junction as an example)

1. Log into your Windows Home Server using remote desktop.
   
2. Next locate the Add-In in Add/Remove Programs under Control Panel and try to uninstall it. (Worth a try).
   
3. Open regedit and locate:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Home Server\RegisteredAdditions\
   
   Then locate the subkey that references the name of the problem Add-In ("GridJunction 1.2.0.0" for example) and delete it.
   
4. Open and then close the WHS Console from within the remote desktop session (to free up any in-use files).
   
5. Navigate to C:\Program Files\Windows Home Server\ and if present, rename the Add-In file ("HomeServerConsoleTab.GridJunction.dll" for example) to remove the DLL extension ("HomeServerConsoleTab.GridJunction.xxx").
   
6. (Optional) Re-Install the desired latest version of the Add-In through the WHS Console as normal.