Q: I’m attempting to install the new Exchange Calendar Update tool on a system that had the previous version installed – I removed the previous version via Add/Remove Programs, but when I execute the installation for the new version, I get an option to repair or remove and choosing either option results in an error indicating ‘This action is only valid for products that are currently installed’. Can someone advise as to what kind of clean up may be needed to get the new version to install successfully?

A: If you have uninstalled the old Exchange tool, then look for and remove the following key if it exists:

     HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall\{9F73F6F4-F3A0-4B0A-A52B-D3B622DE6024}

Try the install of the updated Exchange tool again. The installation should now work after removal of this key.