windows explorer stops working in Windows 7

I am using the Windows 7 64-bit operating system with the Intel G64 express chipset display driver. Whenever the display turns itself off and comes back up i get the message that "windows explorer has stopped working" and the screen is black, all icons have disappeared and the resolution changes from 1680x1050 (recommended) to 1280x1024 or lower. Why does this happen and how do i fix it? I need an answer since we will be upgrading to Win7 in the near future. HELP!!!