Computer does not boot, displays a black screen

I'm at the end of my rope with all of this stuff. I've been in a battle with my computer totalling over 10 hours, and I've made absolutely no progress. Bear with me please, because I'm only 16. My dad has been helping me over the past 2 nights (he is a pretty tech savvy guy) but to no avail. So anyway, here's what's going on.

I came home from a hard day at school, eager to hop on fl studio and make some music. I turned on my computer, and went to the bathroom. When I came back, my computer was on my desktop, with the cursor in the middle of the screen. I wiggled the mouse a bit, and it didn't move. I noticed my keyboard was off as well. I unplugged them, plugged them back in, tried different USB ports, nothing worked. So I held the power button down on the computer, and it shut off. I waited about 20 seconds and turned it back on. The mouse and keyboard turned back on, however I got a black screen displaying 2 options:

"Run windows startup repair" and "start windows normally"

If I select "run windows startup repair" windows loads some files, a loading bar pops up, and then the screen goes black, and doesn't respond at all to anything. I left it sit for around 2 hours, nothing.

If I select "start windows normally" the windows logo pops up, loads for around 2 minutes, and then the computer restarts. It then take me to a screen, where it tells me to insert a boot disk. I have tried a system repair disk, a windows installation disk, a system image disk, all of them load to a black screen.

If any specs are needed I can provide as much as I can. I don't really have an extensive knowledge of the command prompt, but will do as much as I can regarding it.

I have tried adjusting the bios settings, all of the disks, putting it into safe mode, and windows STILL won't boot. I am not amazingly tech savvy, but I have a basic knowledge, so please use as simple directions as possible :) I will provide as much information as I can if needed.

It sounds like your hard drive could be failing, but you mention that it also happens when booting from repair disks. Open up your computer case and reseat the RAM. Make sure to unplug the machine before doing this and holding in the power button for 10 seconds to release any residual power from the motherboard. If that doesn't help, pull out all but 1 stick of RAM and see what happens. You may be fighting 2 problems, hard drive and either RAM or motherboard.

Also, try booting without the keyboard, mouse and any other device except the Monitor plugged into the computer.