Memory plays a very important role in a computer. All applications need to be executed through memory. If the application is large or there’re many applications executing, memory would be consumed up. To solve this problem, Windows uses virtual memory technology, namely, preparing a part of disk space to act as memory, and the part of space is called virtual memory. The virtual memory exists as PAGEFILE.SYS file on disk.
  Virtual memory is only the complement of true memory, so don’t apotheosize it. You know that read/write performance of virtual memory (namely, the read/write of disk) is only one tenth of the true memory performance. Besides, it damages hard disk a lot! Don’t use it as possible as you can, use it as less as possible. The rule is to preserve less and be enough.
 Next, let’s go with several problems and the misunderstandings from users. Of course, this is universal for Windows 7, Vista and XP systems all.
Mistake one: virtual memory should not be set on system drive C, but other non-system partitions
A: wrong! Because as default system partition, the most frequent files disk reads/writes are system files and page files. And when disk is reading/writing, what operation consumes most time? Magnetic head location! No doubt, magnetic head location on one partition saves much time than the one across partitions. So virtual memory on system partition (system default value) executes fastest and is most effective.
Mistake two: the best value of virtual memory is 1.5-3 times of true memory siz