There are several benefits to doing this
Windows 7 – Adjust the Virtual Memory Paging File Settings – Improve Performance
Of the advances offered to users, Windows 7's handling of virtual memory is the most efficient to date. However, as the RAM in a computer increases, the size of the paging file must also increase to accommodate the larger capacity of the computer's memory.
There are several advantages to starting each Windows 7 session with a cleared pagefile. Learn about virtual memory and how to force Windows 7 to clear your virtual memory pagefile when the operating system shuts down.
The amount of memory you can put in your computer is finite. To make more efficient use of the information your computer needs to keep track of, Windows 7 uses a small portion of your hard drive to simulate more memory and make memory allocation more accessible to applications.
