High Memory use when idling

I have Windows 7 Ultimate, 64 bit with 6 GB of Ram and SSD.
After restarting the comp, the memory use is around 23% (of 6 GB).
After working on it for a while, running browsers, spreadsheets, playing a game the memory use just pretty high (with just a few browsers open and Football Manager around 80%).
However, the problem begins when I close all the programs, essentially going to fresh, post restart state. In this idle state, the memory use if just over 60%. This obviously seems wrong. This is over 60% use of physical memory.
What is the issue here, memory leak or something else.
Occasionally, when I have a bunch of things opened, the computer will hang because the memory use is at the peak.

23% at start sounds way to high. Do you use a WD external with Smartware? Are you using any type of automatic backup software? What do you have for anti virus and spyware?
Joe

I don't have any external hard drivee (WM or otherwise) connected to the computer. I also don't have any automatic update. Here is a screenshot of memory resource monitor showing 65% memory use (4 GB) with an idle system. I took this screenshot with everything closed, just a regular startup programs (which use up 23% of memory after restart).

memory resource monitor
If I would add the memory used, as shown in the resource monitor, it wouldn't come anywhere close to 4 GB. So where is all this memory? There is only a single user on this computer.
I've read a lot on this and the reasons vary greatly, I am yet to find the reason for my high memory use.

Do you have Bitdefender for security? vsserv.exe - vsserv, BitDefender virus shield, Delete and Removal Information! If not it may be maleware. Try disabling all your security software from boot. Then keep rebooting and adding one at a time.
Joe

I do actually use Bit Defender for security. I have just decided to open up several high resources programs to max out the memory and see what would happen. After loading a couple of games (each taking about 500 MB), several Adobe applications (Premier etc.,) the memory use went up to 98%. However, after loading a couple of other applications, the memory use went down.
It seems that Windows 7 uses up a lot of memory, which can go up as high as 90+%, however, it releases the memory when needed for new applications.
I still think that it is weird, and I don't know if it has to do with SSD, but I'm just not going to worry about it anymore. It works.