Help with new ram...

Hey guys im back, in the need of some help on my new pc..
So i got my computer custom built for 200 quid, and recieved 4gb ram inside..I play quite abit of games, and a few applications, like sony vegas, CS5, etc etc..
Ive bought new ram exactly the same as the 4gb but this time i only bought a 2, i placed the 2gb inside my machine and it loaded up fine, so now when i right click on my computer and go to properties, i get this..Why is only 3.44 usable?, have i just bought an extra 2gb for nothing?
Helpp!!



Cheers guys!

According to your screenshot, you have a 32-bit operating system installed. Due to mathematical limitations, a 32-bit system has a 4GB memory cap. And of that 4GB, a portion of RAM is set aside for other memory requirements such as graphics card, installed devices, etc. To make use of more installed RAM you'd have to clean install a 64-bit system.