I've been having RAM issues and can't find any fixes for the problem I have. At some point last year, I noticed in my system information it said for Installed Memory: 6.00 GB (4.00 GB usable). I wasn't sure what the problem was or if Windows 7 was just using 2GB to run. However, recently I decided to purchase 12GB of RAM (3x4GB) and when I installed it, I got Installed Memory: 18.0 GB (6.00 GB usable).

OOBE, 4 GB RAM installed on the PC by default. I am looking to upgrade the RAM to 16GB. Before doing that, I wanted to check both the RAM slots, (motherboard has only 2 RAM slots.) I placed the 4GB RAM on the secondary slot and the PC did not boot or detect RAM. The USB 3.0 works on the replacement board, but I can't install the RAM to the second set of slots! Mind you, I have been a part of a RAM upgrade process for a campus upgrading over 1500 PCs. I know how to install RAM. The first two slots work, but that kills the dual channel of capabilities of this board.

I went into BIOS and saw that it sees all the memory in all 6 slots. But, only slots 1-3 are enabled. What's weirder is that slot 2 has a 4GB stick, but only 2GB is enabled. I don't see any option within BIOS to enable the slots or individually increase each RAM voltage.
Specs:
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