I have a problem with my computer locking up with the keyboard and mouse unresponsive and a horrible sound coming from the speakers (I think). This has happened 5 times since I upgraded to a SSD. The first two times it happened the computer was really hot. Fan Speed showed that it was in the 70s. Since then I have gotten the temperature down to below 60. This happened 3 more times last night. Whenever it happens I would have to do a hard shut down using the power button. It boots up just fine without going to the "Windows did not shut down properly. Boot in safe mode or Start windows normally " screen. What else besides heat causes this?