12GB of RAM only 8GB is usable on Windows 7 64-bit

Alright so I'm not sure why in the hell this did the trick. But this computer I'm using has had many previous users, so I had like 9 jdks installed, some 64bit some x86. So I figured I may as well get rid of all of the x86 installations because I had reason to believe that netbeans was running one of these x86 jdk installations, (which it was), because I wasn't even getting much over 4gb of ram usage when I was overflowing my heap space while trying to find a bug.

Anyway, long story short, now it shows a straight 12GB of memory installed on the System page of the control panel, no sub-text about how only a certain amount is available. All from uninstalling some JDKs and rebooting....very odd.

The settings on dxdiag are the same as when I checked before as well. But hey, whatever works =D

Thank you for all the suggestions! especially the dxdiag command, I hadn't been aware of that before this.

You are correct - no video card I've heard of would be stealing that much RAM. Here are all the possibilities I can think of:

• Faulty RAM sticks - swap out your sticks and put in spare sticks you might have, or borrow some from a friend.
• Bad motherboard - in this case, swapping out for other RAM most likely won't work.
• Bad seating - re-seat your RAM (take them out and then put them back in).
• Motherboard and RAM incompatibility - in this case, swap out your sticks for a different brand of RAM.

If you do swap out, periodically check whether your machine shows all of the RAM available.