EXE Name for the creator of a HWND

I have a HWND of a window, how do I get the EXE Name of the program that created that window?

I have used a custom DLL for this previously but it is a pain install a custom DLL into a clients machine, I would prefer to make the API Calls myself.

Anyone have the code to do this? I already have a function setup to enumerate all the current open windows that are visible to the desktop, all I need now is to find the EXE Names of the creator.

Thanks in advance