HP laptop with Intel i2350 chip, Windows 7 Pro. I have had this machine about 9 months. Always hibernate when not in use, only reboot when Windows installs updates. Never had an issue until a couple days ago when it came out of hibernate with no video. Once the hard disk activity stopped I tried ctrl-alt-del but nothing happened. Had to force a shutdown by holding the power button. Then it rebooted normally (although the screen came up saying Windows had shut down unexpectedly). Today it did the same thing. Normally I only use the laptop a few times a week but am on vacation so it's being used, i.e., coming out of hibernate mode, 6-8 times/day.
Does this sound like a hardware or software issue? I should note that I have not made any system (software or hardware) changes recently.