Windows recognises 8gb RAM but only 3.96gb usable

[Ornate]

So my windows says i got 8gb ram and that its not using all of it. And no its not a 32bit OS

https://gyazo.com/c363d351f6f53e82aa5a0c2619c7d7f8

 

[Tradesman1]

Can try raising DRAM voltage + 0.05. Also try both sticks in slots 1-2 from CPU to see if it's a channel problem