This trick is relatively simple to set up and will allow you to earn an average of 100 MB of RAM. It consists of disable Vista’s Aero graphical interface (transparency...) to save RAM. Of course, the latter will reactivate as soon as your favorite game closes.
To do this, open the start menu and click on Games.
Make a right-click on the game of your choice and opt to Customise.
The play menu items of the game in question are displayed as a list (the latter corresponds to the different choices that are offered to you when you right-click on the icon of a game).
Select the order which allows to launch the game, usually the first and click on Change.
On the tab Compatibility, check it out the boxes Disable visual themes and Disable the composition of the Bureau, then click on OK.
Click on Close.
As soon as this game is launched, Aero will automatically deactivate, which will save you both RAM and valuable resources from your graphics card.
Note: Don't forget to repeat the operation for all other games.