Thanks for your help but do you think 40MB is so much?
My original suggestion is still valid: clean up. If you shut down completely your system, and restart it again (from power off status), do you have other startup programs? (Of course you have at least *some*, like tune up for example.)
My point is that you might have "too many" processes doing "too many" things in the background. Although 40MB seems a little bit higher than usual, it depends on what exactly is going on in your particular system. So, it is a bit higher than usual, but yet plausible.
Just to give you an hypothetical example, if Tune Up is working in the background, then avast may be watching whatever is happening there too.
So, go back and read the previous suggestions, and decide by yourself it this is worth (you could use the free memory available as a measurement, instead of the used one).
If you have any particular question about the suggested procedures, just ask.