HELP ON MEMORY!!

i got the 4GB (2x 2GB) CORSAIR XMS2 memory sticks. I plugged them into the dual share memory slots. Timing 5x5x5x18, voltage 1.850v, but when i go to System in the Control Panel, it only reads about 2.75GB... is it suppose to be like that or i need to go do something in the BIOS??
EArly thank you!

If you're using a 32-bit OS, it will show that way. The OS can only address 4GiB maximum, but some of that is used for other system components, so you won't see the full 4GiB.

Whats the rest of your system components? Some boards ie Asus have a memory remap setting in the bios which might help