Might be useful, especially after the last 2 posts.... I use a little utility called PC Booster V3.0. I am not usually a fan of software "boosters" cause I have tried loads and most of the time they are crap, but this works quite well. It site on top of all windows and shows a live reading of total memory, and available memory, with a "Free RAM" button. This app is NOT for the faint hearted.... DO NOT look at it when you are using Terragen, it is frightening..... very frightening
You can watch your memory just dissappear. But if you click on the "Free RAM" button it forces a release of non essential memory across the board, and it does actually work, cause if you fire up Task manager and go to the processes tab and then click the free RAM button you can see the memory decreasing for a lot of apps.
Its not the be all and end all but it does actually work. In case anyone is interested its at
http://www.bluesquad.com (and no, I don't work for bluesquad
)