The WP7 emulator can be painfully slow if you don’t check two simple things,
1. One, is check the DDI version and the driver model, for doing this you should go to Windows button and on the search/execute area type dxdiag & pulse return. There should appear the DirectX diagnostic tool, once there click one of the Display tabs and on the controllers, validate the DDI version. It should be 10 or better. Also check the Dirver model, should be WDDM 1.1 or better – if it appears, as it does on one of my laptops but on my desktop it does not – note that I have a three monitor display working with two GPU, so I guess that’s why…
2. Second, enable the BIOS virtualization support, as this is set to disabled on most motherboards. This can significantly increase the emulator speed as it will run directly on the CPU which is better than a layer of software – as a “man in the middle” which is logically slower.. this will mean getting into your BIOS and rebooting your system.
For more insight on WP7 performance, this talk is a must : http://live.visitmix.com/MIX10/Sessions/CL60