it could be a few things: 1. Wake on LAN... that's a BIOS setting, turn it off 2. "last power state." this BIOS setting sets the state of the PC when AC power is restored. the settings are off, on, and last state. If it's set to on... if you have a small power outage, when power is restored, the PC will turn back on automatically. Set it to "last state" 3. Someone is using your PC/flocking with you. Solution? Set a CMOS password. Set the password somewhere on the desk... if it's used then someone is trying to access it. If not... then it's something else, or the person is an idiot, or genius if (s)he see right through your plan.