You cannot use the mouse or the keyboard to wake a Windows Vista-based computer that has an integrated graphics processor and a a graphics card
Consider the following scenario:
- You have a Windows Vista-based computer.
- The computer has both of the following:
- An AMD 780G Chipset with ATI Radeon HD 3200 integrated graphics processor
- An ATI Radeon HD 2400 Series graphics card
- You have the ATI Hybrid CrossFireX feature enabled.
- The system enters the Sleep (S1) mode.
In this scenario, you cannot wake the computer by using the mouse or the keyboard.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB959345.