I just built myself a new system and with 16GB of memory, I have turned off the virtual memory. It seems to me that real memory is faster than swapping things back and forth from a hard drive and it should save wear and tear on the hard drive. Maybe the operating system only uses the pagefile if it runs out of real memory?
Virtual memory isn't something that can be turned on or off. It is a central concept in Windows memory management, as important to how the OS operates as a heart and lungs are to you and I.
Virtual memory is a complex system involving the CPU and OS. This system provides to each process a private virtual environment with an address space of 2 GB (in a 32 bit OS) in which code and data is stored. Note that the size of this address space is completely independent of RAM size. To a process this is what memory is. A process knows nothing of how much RAM is in the system, where it is, or how it is being used. RAM is managed by the system memory manager and it's operation is completely transparent to an application. A process can learn some of these detains but few do, it being little more than useless trivia.
This concept of virtual memory is nothing new, being used in every Windows server and desktop OS for some 20 years. And it has been used in large computer systems since the 1960s. Linux and Mac OS X follow the same principles, differing only in the details.
A virtual memory system offers many advantages to both developers and computer users alike. Modern operating systems wouldn't have near the capabilities they have without it. Unless the system is under severe memory pressure the performance is very good.
Unfortunately, Microsoft has done little to educate the public about this. In fact, many computer professionals lack even a basic understanding. In much user level documentation it is described as "using a file on the hard disk as if it were RAM". A serious misrepresentation if ever there was one, and one that been the cause of much unwarranted criticism of how Windows manages memory.
The pagefile is a small but important part of the virtual memory system. It's purpose is to optimize the operation of the system and it generally works very well. It works by providing a place where the memory manager can store rarely used data, thus relieving RAM of this burden and allowing it to do what it does best.
Unless you have a specific need and you understand what you are doing (and you can't learn this by reading a few forum posts) it is best to leave pagefile configuration on default settings. Many people have disabled the pagefile in the belief they are benefiting performance. In most cases they are only fooling themselves.