Dear forum, after being in contact with PTC support, I post my question here. Starting CoCreate PE for the first time I expected to see a login sceen. But instead I only get a message box "Keine gültige Lizenz für CoCreate Modeling Personal Edition" (no valid license for...) I am trying to use the German edition on XP Home After being pointed to this forum, I did read all the applicable threads in the forum and also followed the troubleshooting guides there. I do also not have the mentioned Spyware Doctor installed. Even after disabling my Avira Antivirus and the Windows firewall I still get the same ""Keine gültige Lizenz für CoCreate Modeling Personal Edition"" message right after the splash screen. I also produced following OLAPE output: (not sure if this helps) OLAPE Debug Output ================== UTC time=02.05.2009 08:49:39 Local time=02.05.2009 10:49:39 OS version=Microsoft Windows NT 5.1.2600 Service Pack 3 Windows XP Home Platform=Win32NT command-line argument[0:0000000000] = 3D SDLANG = german trying to assign localized messages using a ResourceManager culture = de-DE culturePrefix = de/ finished to assign localized messages using a ResourceManager reading Windows session data username = Besitzer hostname = PRIME reading stored account data baseKey(OneSpaceModelingPE) == null, creating registry keys Maybe you have another idea? I would be happy having it running!