Says only half my ram is usable

DGK Waffly

Honorable
Jan 24, 2014
4
0
10,510
I just got windows 7 for Christmas. I have 1 stick of 8 gb ram. When I go into my system preferences it tells me that I have 8 gbs of ram installed, but underneath says (3.94 usable). If anyone could help me out here, that would be great. I plan on giving my system a semi heavy load and don't want to be bottle-necked by my memory. I am using 64 bit windows.