You may be unable to use a remote control to wake up a Windows Vista-based computer after you put the computer to sleep (S3)
After you put a Windows Vista-based computer to sleep (S3), you may be unable to use a remote control to wake up the computer. However, you can use the mouse or the keyboard to wake up the computer.
This problem occurs if you install a TV tuner that has an integrated infrared (IR) remote control in a specific Peripheral Component Interconnect Express (PCIe) slot.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB967329.