Windows example of Virtual Memory:
Virtual memory has been in existence in Microsoft Windows operating system since Windows 3.1. WIN386.SWP is a hidden file created by Windows 3.1 for use as a virtual memory swap file. It is generally found in the root directory, but it may also appear in Windows directory. Its size depends on how much virtual memory the system has set up under Control Panel - Enhanced under "Virtual Memory." If a user moves or deletes this file, Windows will come up with an error "Swap File error" the next time it is started.
Windows automatically sets the page file to be 1.5 x physical memory. If you run memory intensive applications on a low physical memory system it is preferable to manually set the size to a value higher than default. Additionally, fixing the size of the swap file will prevent it from being dynamically resized by Windows. This resizing causes the swap file to become fragmented, resulting in reduced performance.
