Virtual Memory

The main memory in your computer is the physical memory, or RAM (random access memory). This physical memory generally is not large enough to hold all of the running programs so Windows sets up some additional virtual memory as a file on the hard drive. It then swaps portions of the programs between the physical and virtual memories, always having the currently active portion of a program in the physical memory.

Windows sets virtual memory size from 1.5 to 3 times that of the RAM. Windows then manages the actual size, expanding and contracting it as needed within these limits – provided you have adequate space on the drive. You can override this and set the minimum and maximum limits of virtual memory yourself; however, I usually do not recommend this for most users.

The message that virtual memory is low means that the programs you are running need more space. Windows cannot find enough within its limits. If the message keeps popping up then it is time to add more RAM in the computer.