Ok, I have removed one memory stick and it worked.
Then I put it back in and it worked as well.
But not long after using the computer, it froze one me.
When I restarted the box, same beeping as before.
I have removed the second stick, and still nothing. I have switched the sticks, and the computer booted fine again. Sounds to me like one memory stick (if not both) is bad.
The memory is a Corsair double pack of 512MB DDR2.
Board is currently ASUS M2NPV-VM, I used MSI also, the system was doing the same thing, but it didn't produce any kind of beep.
PSU is 380W, with 18amps for 12V+.
Video card is Radeon X800 GTA, 256MB, PCI 16x.
Since I got the system going with this board, I'll tell you again what the main problem is now.
After running for a while, the system freezes. When that happens, I am not able to restart the computer for a while. Not even Turn off/on. I have to wait a couple of minutes and then it usually works.
Right now I'm trying to run on the one memory stick that I started the computer with, see if it will be ok.
The problem shouldn't be with the video card, be cause at some point I wasn't able to start it without the video card, using only the on-board video.
Any ideas?