New 2003 Server not recognizing all Ram

I just bought a Dell PowerEdge 1800 computer and installed the Server 2003 SP1 software on it. I have a raid controller in it and have 2 Raid 1 arrays and a dynamic volume--making 5 HD in all.

The computer is a duel core Intel Xeon CPU with 2.80 Ghz processor. I have 4G of ram installed.

When I boot into Bios, I can see the 4 Gs of ram, but during POST it says I can only use 256MB of Ram. When I look at system properties after boot-up, it says I only have 256MB of Ram.

Does anyone know how I can get my server to recognize all 4Gs? I want to solve this before I start to create my AD and do the other server thingys I want to do. Thank you.

I have just reset both of my 2G Ram Sticks. I powered down my computer, unplugged the computer, took out the Ram sticks, an replaced the Ram sticks.

When I powered on my computer, it still says, "Amount of available memory limited to 256MB.

Grr....arghh!

Try using one stick at a time & boot up to see how much get recognized.

You could have either a faulty MOBO?

I tried what you suggested. It did not work. I rebooted into bios and saw a line I did not recognize called, "OS Install Mode." It was set to "On." I set it to "Off" and saved and exited bios.

When I booted up again, the problem was solved!