User32 API Window List

[Robin Day]

Hi,

I am looking to (hopefully quite simply) populate a drop down list with a
list of the currently open windows (applications) and their respective
HWND's
I have found various snippets using GetWindow and FindWindow from user32.dll
but have been unable to get it all working.
Any help / code examples would be much appreciated. Preferably in C# but any
examples would be useful.

Thanks in advance,
Robin