I've got a Dell Studio desktop. I shut down the computer last night, like normal, and this morning I boot it up but nothing happens. Everything was working fine last. I checked all the cables, I checked that the power is on - the power surge protector is lit, the printer, monitor and modem al have power, and the green light on the back of the tower is lit. I tried unplugging the power, all connections and held the power button down for 15 seconds and then reconnected everything and tried to start it, but nothing.