WTF is Window Server in my Processes ; MBP won't sleep

Windowserver is a system process that basically draws all the graphics of all your GUI apps. That is definitely not your problem if you're trying to diagnose an insomniac MBP. Check your startup items. Check that there's nothing that might keep your MBP awake. You could even disable all your startup items, then try restarting and see if the problem is solved. If that solves it, turn your startup items back on one by one to figure out which one is causing the problem. You could also try miscellaneous stuff like resetting the PRAM and repairing permissions, which tend to fix problems on occasion.

Cheers

 

Just checked the process on my BlackBook, and WindowServer is using under 3%.

"WindowServer draws everything you see on the screen. It acts as a mediator between applications that want to draw on the screen and the graphics hardware. When an application wants to draw something, it establishes a connection with WindowServer, tells WindowServer what to draw, and WindowServer handles the drawing / compositing / Quartz Extreme hardware acceleration to finally produce what's seen on the entire screen."

(Quoted from http://forums.macrumors.com/archive/index.php/t-59082.html)

 

disconnect all peripherals when you try to sleep the machine, to make sure they aren't keeping it awake.