Unless you're running out of memory, it's not a problem. Windows is using as much of your memory as possible to make things run faster. Having more free memory will not make your computer faster, because free memory is doing nothing.
How TO Reduce Physical Memory USage in Windows 7..
I am Using 2 GB Ram and my physical Memory goes ups to 60 % . What will have i to do
go into start up tab
turn itunes off
turn flash update off
turn everything off other than anti virus software
reboot and recheck
if still at 60 precent run malware byte scan and anti virus scan.