8gb ram installed 3.93gb usable. win 10 64 bit

[charlesssv7]

In system properties it says i have 8gb ram installed but 3.93 gb usable.
Is there something wrong with my pc?

proc: ryzen 3 1200
mobo: asus prime a320m k
ram: 2x4gb gskill aegis 2400 mhz

 

[charlesssv7]

in my bios information memory is still 4096MB. does that mean im just using 4gb of my ram?