RAM usage reach 80-90%

[wagpofafi]

RAM usage reach 80-90% when installing games, high-end games like NFS the Run, Starcraft 2, Rainbow Six Vegas,
when i install the games my memory usage always reach to very high 80-90 and sometimes 98% and after installing the memory usage doesnt go low, and i have to restart my laptop for my ram to run in normal usage. when i install applications like MSword2007 and microsoft visual studio 2008 my memory usage does'nt reach that high. im using windows 7 home premium and i'm using Asus k53sv with i5-2430m with 4gb ram.any one know how to fix the installation problem?

[Geek-9pm]

Why is this a problem? Restart you PC after installing significant software.

[wagpofafi]

Is it normal when using windows 7?because i think memeory usage should automatically run normal when there is no work load process that is being executed and i dont remember experiencing this when i was still using XP?

[Computer_Commando]

It's normal.  Unused memory is useless memory.