Why does the Emulator not work on my machine when I use XNA?

Unlike previous versions of XNA, where you only needed a 3D card if you were writing 3D games, in XNA 4.0 the emulator checks for adequate graphical abilities before your program gets to run. This means that even if your game only uses 2D SpriteBatch operations, it still needs DirectX 10.0 support to get to run. The good news is that this test is only performed on the way into XNA games, and so you can develop Silverlight Phone applications on machines with no graphical hardware acceleration. But if you want to use XNA your machine must support Direct3D 10.0 and Windows Driver Model 1.1. The release notes for the Developer Tools have more information on this, and a registry tweak you can use to try and persuade the emulator to use your hardware, even if it shouldn’t. This didn’t work for me, but a driver update did.

If you are noticing poor performance you might want to check your BIOS settings (if you are feeling brave) and turn on ROM shadowing if this is not already enabled.

There is now a thread on the Windows Forum just for emulator problems. You can find it here.