how can i make my pc run 7.90GB of RAM usable again?

saif_1996

Honorable
Jul 24, 2013
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0
10,790
my PC has 8GB of RAM and it said i had 7.90GB of RAM usable but now then it said i had 3.16GB of RAM usable but then i fixed it by this video

http://www.youtube.com/watch?v=4UgTnRcXR5o

and it give me a boost to 7.16GB and i want it to go back to 7.90GB cause i think 1 GB of RAM that isnt usable is allot

so how do i fix it i really need help please