[Solved] Less than 4GB available on 64bit Vista

I have a new system build with an ASRock P45XE. I have 2 x 2GB Mushkin memory installed. This displays as 4GB if I go to My Computer->properties however, I am getting mixed results in other tools that display my installed memory. BTW, I am running 64 bit Vista which should allow me over 3 GB.

When I boot my PC, the bios reports that it sucessfully checked 3264MB. When I ran 3dMark06, it reported that I have 3328.

I ran memtest 86+ off of a USB stick and it reported various things, but somewhere around 3364MB. I've never used memtest before, but I did try running the memory sizing routine within memtest. this froze everytime, but after reading the manual on their web site this is not that uncommon.

I've installed some other memory on the board and this seem to be displayed correctly, however I did not have 4GB so I was not able to do too much of a test.

Where should I go from here? I just bought the mobo and memory, so I could return them, but I'm not sure if there is a problem or not. I've not experienced any crashes, but I do want to ensure that all of my available memory is being utilized. I got a nice 4Ghz overclock out of my E8400, so I'm a little reluctant to change things.

any suggestions on tools for testing the memory, or could someone confirm that what I am seeing is "normal"?

That was it. It was set to disabled. I changed it to enabled and now everything reports 4GB.