Black screen and strange sounds from my computer.

I cant connect to my computer right now, but when i turn on my computer it usually say one bip sound, but now it say it like this bip biiiiiiiiip bip, and when i get lucky enough that my computer wants to turn on properly, the screen turns black. Its really annoying, cause 1. I have to make homework on that computer, and some important stuff for my exams and work is in there, 2. I cant play on other computers, my sisters laptop cant play a god damn game.

I wanna say that i rebooted my whole computer cause my computer got so laggy, then after i rebooted it, i installed all the games again, and some other programs. And then there goes like one week and then BSOD start, i fixed it by writing threads in here, but now i cant.
But my friend said to me that i had to uninstall the drivers if i want to reboot my computer back to factory. And i didnt reboot my computer with a CD.

EDIT: Now it also show red screen, grey screen and white screen

The change in beeps mean there is a hardware issue. Go to the manufacturers web site and find what the beep code you hear means.

Depending upon what version of BIOS your motherboard has, those beep codes may vary from a Phoenix BIOS to an AWARD BIOS.

What you're describing as: short - long - short beeps; sounds like a RAM memory problem. Try removing your RAM sticks (after shutting down your computer and unplugging the power cord) then re-seating them firmly, ensuring that they're fully seated and locking tabs engaged on the ends of the sticks.

Also while you're in the computer make sure the video graphics card is fully seated and locked in too.

I took it out, and when i look on it, there is dust on it alot. Can the dust be the problem, also some wires in the computer was touching the ram cards.

Dust can cause shorts, choke fans, block airflow, and in general will cause parts of the computer to overheat. If components have been damaged from overheating too long then the damage is already done.

It's likely either overheating or something else resulted in a hardware failure, that's what the beeps mean. As everyone else already said, you need to reference you manual to see what the beep code stands for as that'll tell you what the problem is.