These sorts of errors are most often caused by problems with your environment variables or registry entries.
You could take a look through your environment variables - both the user and system tables - and remove any references to older PADS versions. After that, re-run the Configurator.exe that is under the "win32" sub-directory in your PADS 9.4 installation. If that doesn't work, you should open a Service Request on SupportNet.
Also, here are some links to some Communities Docs that may come in handy: