Only 3.46 GB out of 16 GB usable, can't fix problem

StrangeCharacter

Reputable
Jan 27, 2016
1
0
4,510
Specs:
Windows 10 Home
ADM FX(tm)-6300 Six-Core Processor
16 GB RAM (3.46 usable)
MSI 970A-G43 Motherboard
GTX 760 Graphics Card

So I had a problem with my computer where I had to pretty much put another OS into my PC, I had to install Windows 10 again from a USB Drive .And when I did this, almost everything was running normally after that, except that I lost all of my files and that my Graphics Card wasn't working properly at first, but I fixed that. Then I realized that so little of my RAM is usable. What could have happened to make most of my RAM unusable? Is my RAM being taken up by the new operating system? I tried running a Windows Diagnostics Tool and it found nothing was wrong. Is it just my RAM that is messed up or is something wrong with my motherboard? I'm not very good with computers so I'd appreciate all the help and suggestions I can get. Thank you