I discovered this program by chance, and its a freebie - freeware, not time limited, not a trial.
I won't go into much detail here as I would only be reproducing the review on the site I,m suggesting you visit.
Many programs 'leak ram' and this little prog. addresses this.
A certain well know browser, is said to be notorious in this respect.
The name of this program: ''Cleanmem''
You can schedule this to cut in regularly, mine is set in 1 min intervals, and I've noticed a big difference in my available ram.
Enough said, here is the link: CleanMem: RAM/memory cleaner that actually works | Freeware Reviews | dotTech [.org]
Be interested to know if anyone else found this useful?