1). Start any application, say Word. Open some large documents.
2). Press CTRL+SHIFT+ESC to open Windows Task Manager and click Processes tab and sort the list in descending order on Mem Usage. You will notice that WINWORD.EXE will be somewhere at the top, using multiple MBs of memory.
3). Now switch to Word and simply minimize it. (Don't use the Minimize All Windows option of the task bar).
4). Now go back to the Windows Task Manager and see where WINWORD.EXE is listed. Most probably you will not find it at the top. You will typically have to scroll to the bottom of the list to find Word. Now check out the amount of RAM it is using. Surprised? The memory utilization has reduced by a huge amount.
5). Minimize each application that you are currently not working on by clicking on the Minimize button & you can increase the amount of available RAM by a substantial margin. Depending upon the number and type of applications you use together, the difference can be as much as 50 percent of extra RAM.
In any multitasking system, minimizing an application means that it won't be utilized by the user right now. Therefore, the OS automatically makes the application use virtual memory & keeps bare minimum amounts of the code in physical RAM.