tedathome
Hope I can help you out
I have dual core with Vista, sp2 and 3 gigs of ram.The ram never gets used above a gig and a half whether idle or at top speed. Is there a fix for this?
if the meter your using only shows you using half your memory whether at idle or full throttle, it can be a few things.
all of a sudden with no system changes1) either the meter is not working properly: fix use another meter
2) you may have a bad stick of ram: fix find and replace bad stick of ram
3) stick of ram not inserted all the way: fix seat ram properly into
4) could be a bad chip on motherboard
if system changes been made like new mother board, new ram sticks, or OS if so check5) is DIMMS (dual in-line memory module) seated in the proper spots
6) Are both of the memory sticks and SPD settings/timings identical: fix Buy ram sticks that are sold together in one package
7) at POST does it shows 3 GB total

if your BIOS is update
9) Enable memory remapping in BIOS
10) aged computer with new os like windows 7 sometimes might only recognize 1/2 the memory
11) does mother board support the new type of ram
12) could be a bad chip on motherboard
also could be other problems but this is what I could come up with off the top of my head.
Hope this helps out, it took me over a month to figures out I had a bad stick of ram. funny thing was it passed 3 totally different memory tests.