I held down the power button for 5 seconds, it made a pretty loud noise (it startled me), the screen shut off, and I turned it back on. There were options like "start in safe mode" "start in safe mode online" and "start windows normally". I chose to let it start up normally.

But now my computer is making sounds that sound like very quiet thunder or snoring. My computer now looks normal, but it doesn't sound normal.