I left my computer running for maybe 3 weeks and I've always done this and never had anything happen. I came home and the computer was on, but the screen stayed black and the fan was going somewhat crazy. So I just held the power button to reboot. After that, I would get to the home screen after typing in my password, 2 mins later, the screen went black again and fan went crazy. I tried this like 5 times and still the same results.
So I decided to open up my computer and get some of the dust out thinking it was just overheating. After doing this, I tried turning on my comp and now on startup it beeps 4 times, pauses, then beeps 4 times again and continues this process. Does anyone know what could be wrong with it? I have year and years of pictures and files that I need (i think the hard drive is definitely fine). I just don't want to have to buy a completely new desktop... If anyone has any ideas as to why this is occurring please help me out. Much appreciated, thanks!