For a good looking GUI, it might be nessecary to have multiple window icons in one applicatino, for this purpose I have created a tool-vi that uses the windows API with the WM_SetIcon message and the LoadImage method to change the icon of a single VI front panel window:
With this VI you can change the icon of a single front panel window, here's alittle video showing this feature
Hope you enjoy this little tool, if you have the possibility to test/alter the VI for Windows 64-bit, Mac or Linux, please post your updates!
EDIT: There was a small bug in the program that caused it to work for only one VI at a time, now it works for multiple VIs, you can set and reset at any moment you want, the tool should remember what the original icon should be. It is not advised to multiple times use a set and then use a reset.
To use this tool you'll need to have the OpenG Application Control toolkit installed.