(64b W7Pro) Satellite U500 using 3+ Gb RAM at idle???

Hello 7ers,

Okay, for the past four days or so, I've been using my wife's Toshiba Satellite U500 to connect to the net through a USB-tethered Sony Ericsson Elm, with my B300 connected to it in ad hoc.

So, today was the first time I actually attended to the machine in four days, and it was slow as a snail to respond for about three minutes or so, then it came back to normal. So I checked the task manager, and found the machine using about 3.3Gb of RAM, even after I closed Firefox and what not. So where's all this RAM going? (Note that I had installed an additional 2Gb of RAM last week for a total of 4Gb.)

In other words, should I even worry about it? It was running fine on its original 2Gb of RAM until last week (albeit with the previous 32-bit version of 7 before I did a clean install of the 64-bit version), but it was using most of those 2Gb at idle just the same.

Thanks in advance.

You could also use the Resource Monitor for a graphical overview of how RAM (and other resources) are being used.

Resource Monitor

What I meant to say was that the machine was slow to respond after having sat idle for the past four days, but that cleared up in about a minute or so, and it was behaving normally again. I then checked the task manager and the resource monitor, and although nothing seemed out of the ordinary (applications-wise), I was a little surprised to see so much RAM being used.