It can be irritating when you bump your mouse
and it wakes up your pc.

I Found this useful tip on…
http://www.gordonknight.co.uk

Open command prompt and type “powercfg -devicequery wake_armed”
it will show a list of devices that can wake your PC.

For example…

powercfg -devicequery wake_armed
Standard 101/102-Key or Microsoft Natural PS/2 Keyboard
Microsoft USB Wheel Mouse Optical

f you want to disable the mouse type….

powercfg -devicedisablewake “Microsoft USB Wheel Mouse Optical”

Now why for Christs sake cant you do that via control panel ?