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 1680×1050 (recommended) to 1280×1024 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!!!