Less usable ram then available

[amin_16]

I had recently 4gb ram which was all usable.I then installed 2gb ram more now it shows 6gb available but only 1.93 usable.i did the msconfig thing also the advance tab one to increase the page memory.i thought i had dimm slot problem so i changed it aswell but no use its always the same.installed the windows once again but not working i also removed the ram because i thought it was malfunctioning.now it shows 4gb 1.93gb usable.plz help nothing is working i play pubgm on pc but it requires atleast 3gb.

 

[amin_16]

Somehow it got fixed after i downloaded cpuz??