SP3; Win 8.1 i5 CPU, keyboard attachment, and docking station. IN Power Saver mode. Plugged in all the time. (well, 95% of the time) Initially, when I put the keyboard 'up', the SP3 appeared to sleep. Perhaps it did not. I needed to input my password to waken or have access to the SP3. So, I was playing around with the Power Options (I'm learning about this device still a few months into it) and went to Chose what closing the lid does. I clicked on Chose what closing the lid does options and noticed that all the drop down options were then blank. I clicked on the drop-down button (mistake?) and then there were three options for the plugged in mode: Do Nothing, Hibernate and Shut Down. I chose Hibernate since Sleep was not then an option. Hibernate took / takes longer to start up again. Was the SP3 sleeping previously, prior to Fi-didleing with Power Options, when I closed the lid, so to say, or put 'up' the keyboard? I then noticed after disconnecting the keyboard and rebooting (had read somewhere this reverts SP3 with keyboard to default keyboard mode) and poof: Sleep became an option in Power Options and was defaulted to all four situations: for Battery and for Plugged In, 1) When I press the Power Button (SLEEP) 2) When I close the lid (SLEEP) SLEEP was showing as the selected option. I touched nothing, and SLEEP seems to be occurring again, as I prefer it. A neat thing I seemed to have learned. Sleep is a default function.