Widows won't use all of my RAM???

Okay, I have windows 7 64-bit and when I start my computer it says "Installed memory (RAM): 12.0 GB (7.99 GB usable)" but on the odd occasion it says "Installed memory (RAM): 12.0 GB (3.99 GB usable)" I have flashed my BIOS to the newest version and my BIOS recognizes that I have 12 GB of RAM. But for some reason I cant use the full 12 GB, also my mother board supports up to 24 GB of RAM. This is my motherboard but its not a refurbished. I also have checked that msconfig is not limiting how much my computer boots with.

If anyone has any ideas on why my computer is doing this it would be very much appreciated!

What does your Bios see for ram amount?
Then show us a picture of your Resource Monitor like this.

I'm thinking you got that from your Bios, is that correct?

Where are you getting the figures of 3.99 and 7.99 usable ram?

Well all the numbers add up. What it is telling you is yes you do have 12 gigs installed. Your are using for hardware,standby and unused the rest of the ram. Now to understand what those things are just hold you cursor over each one and you will see a short explanation of what they are.
Hardware
Modified
Standby
Used
I really don't see a problem.
Does you computer operate correctly? Remember that Windows 7 handles the way the ram is used and it does a great job doing it. When you start do things on your computer Windows 7 will adjust things cache, standby and the like. If you want to free up ram you have to turn things off in the background. If things are working as they should that is not a must to do. Ram is there to be used.

Very sorry I missed that. That is high for hardware to the best of my memory. Lets do a little research and see if we or someone else has a answer. I will be back when I find something.