Win7 comes with directx 11 beta and you need directx10 or below I think. Reinstall directx to 9 or 10 and you should be good.
If not its probably your drivers
or try this
Right click the desktop icon, Click properties
Click Compatibility Tab
check the box for Run this program in compatibility mode for:
Select Vista from the down drop box
check the box for Run this program as an administrator.