I've downloaded all the updates, but I can't get the graphics card driver because I don't know the graphics card (won't display anywhere, since the machine doesn't recognize it). I've also installed directx 9 but the problem still occurs (no sound, 16 color, doesn't recognize as 2k os).

Try this little system information utility:

SIW - System Information for Windows - Software, Hardware, Network

It will tell you just about anything you want to know about your system. Its an executable, so it doesnt have to be installed. Just download it to the desktop, or your favorite folder and run from there. It should see your graphics card, even if windows doesnt, and tell you make, model, ..ect.