In this previous question <How to get COM Server for Excel written in VB.NET installed and registered in Automation Servers list? there is an example of how to create the full path to a registry key using VS 2008. Everything in the previous answer works correctly except the full path that I am setting (using the registry editor in VS) for mscoree.dll is not working (meaning it seems to do nothing). The full registry path is: HKEY_CLASSES_ROOT\CLSID{my_GUID}\InprocServer32(default) and the value I am setting is: [SystemFolder]mscoree.dll I can put anything (including hardcoding the full path) but the setting does not seem to matter and the registry always contains mscoree.dll without any path. I have tried adding another value to the registry path via VS and that works correctly including having the full path as specified by [SystemFolder]. The reason I need the full path (as explained in the previous question) is that without the path, Excel generates an error when the automation server is selected as it cannot find mscoree.dll (interestingly even though I receive an error the registration works OK). I am doing the install via a setup project which otherwise works fine. I am installing on a VISTA*64 system but have gotten the same error on other OS's. Does anyone know what I am doing wrong?