I'm not sure where to look or what to do (I've searched this problem) but a lot of times when I get up from my desk, the computer completely freezes, everything seemingly gets disconnected (no lights are on) except for my monitor, and my programs dont treat it like a computer crash (Firefox dosent ask if I want to restore my session, it just opens the tabs and windows), and I have to hold the power button down to turn it off, what gives?