HP All in One Won't sleep Automatically

[Sphillips21]

I am experiencing a problem that is driving me nuts! Even though I have my pc set to go to sleep after a certain period of time (I've changed that amount to see if it helps), IT WILL NOT GO TO SLEEP! The same is true for getting the display to turn off automatically. After googling and trying to find a solution on my own I have tried a couple of things that looked promising. However, so far nothing has been effective. The one thing that looked like it would have been the answer was to go into advanced settings and make sure that under multi-media that it was set with the option for the computer to go to sleep. That was already selected that way. Please help!!! The other problem which I am sure is related somehow is that when I I click on the start menu and select power and choose for the pc to go to sleep....I've walked back into the room later to find my pc WIDE AWAKE AGAIN! I am certain that the computer had gone to sleep before getting up from the desk.