Memory Issues

[worldsmart02]

I have OCZ2P800R21G (2GB), I added additional 2GB with this kit OCZ2P800R22GK. The problem I have is my pc only sees 3GB not 4GB. I am running Vista 64bit and my board is Asus p5b deluxe.

Whats the problem here ?

 

[DSF]

Does the computer recognize all 4GB in the BIOS?

 

[n7]

Enable memory remapping if it isn't.

It's under Chipset > North Bridge > Memory Remapping IIRC.