Common key locations for Office installations are these
- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office
- HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft Office
Unter this key you will find subkeys for different versions of Office (15.0: 2013, 14.0: 2010, 12.0: 2007, 11.0: 2003). You can search for the value “ProductName” in order to look through the different license keys and find the right one. By deleting the key in which this value is stored, you can remove wrong information. On computers which had MS Project installed, one of the ProductName values should have “Microsoft Project” filled in. So you could then delete the hash key in which this value is stored.
We recommend not deleting the whole Office version key (i.e. 12.0, 14.0 or 15.0), as the data stored in there are used also by still installed Office programs. Before deleting registry keys, please do a backup of the registry.