I have an HP PAvilion 15t-n200 Notebook PC (not touch-sensitive), and am running Windows 7.
I was playing League of Legends, when the computer suddenly began beeping steadily/consistently into my headphones and my cursor started moving excruciatingly slowly. When the headphones were removed, the beeping continued, this time through my speakers. CTRL+ALT+DELETE resulted in a screen that said "loading security options" or something to that effect, where it stayed indefinitely. I put my computer to sleep, brought it back, and managed to start my task manager using my keyboard. My mouse continued moving slowly and not clicking, and the beeping persisted.
I almost always have my laptop plugged in to a cooling fan (and I did this time), and the laptop was not hot/overheating. I have MalwareBytes and Avast! and ran scans with them just yesterday, which found nothing. I have had a similar problem (but not to this degree of severity) before- last night my game was lagging at least a second behind my actions, and sometimes when i pressed buttons/clicked (usually in the middle of a big event with lots happening on the screen), I would get some random beeps. I blamed the fact that the fan was not connected and that my computer was probably "tired", and returned to play 3 more games of League.
I just bought this laptop less than 3 months ago, and I am severely disappointed that something this severe is happening so soon in its lifespan. I have not abused it nor has it had any viruses.