Windows Task Manager Ram Usage Issue

Currently I'm having a problem with the windows task manager saying I'm utilizing 4gb out of my 16gb of ram when I am idle on my main computer. I did a comparison on my secondary computer and when I'm idle the task manager shows that it is only using 1.5 gb to 2gb of ram when idle. Is it normal for windows to be utilizing 4gb of ram when idle?

Not at all. Windows should be utilizing between 600MB - 1GB of RAM (depending on version) when idle. Use Process Explorer to find out what is all your RAM. I find that Task Manager doesn't tell the whole truth.

http://technet.microsoft.com/en-us/sysinternals/bb896653

if you go to taskmanager and look at the process's you should be able to see whats suin the ram up, currently im at 18-19% ram usage of 8gig, i think 4gig usage is a little high and something is eating it up.