Crashes When PresentParams.Windowed = true (Managed DirectX in C#)

[res7cxbi]

Hi,

I took a look and followed the Game Development Tutorials by Derek on
Coding4Fun and found them to be (in my opinion) the best beginning game
development tutorials ever made on the face of this earth :-)

But I got this really weird problem....

When I set PresentParams.Windowed = true in the code, it works
perfectly. But when I set it to false, it crashes. I ported the C# code
to native C++ (quite successfully too), but with same results.

Do I need to do anything else to the Main Form so that it works
fullscreen? Or am I missing something obvious? I'm sorry, I new to this
DirectX business.

Thanks in advance.