If you are setting up Qt Visual Studio Addin in Vista and get this message when trying to add the Qt folder (in Qt Options > Qt Versions):
The platform “Windows Mobile 6 Professional SDK (ARMV4I)” is not defined within Visual Studio. Make sure you have installed the required SDK.
-or-
The platform “Windows Mobile 5.0 Pocket PC SDK (ARMV4I)” is not defined within Visual Studio. Make sure you have installed the required SDK.

You need to make sure you have Visual Studio running in Administrator mode. You also need to be in Administrator mode when creating your WinCE project.

You can also type in the command line: checksdk -list to check that you have the correct Windows CE SDK installed.