If your computer lacks the random access memory (RAM) needed to run a program or operation, Windows uses virtual memory to compensate. To find out how much RAM your computer has, see Find out how much RAM your computer has.

Virtual memory combines your computer’s RAM with temporary space on your hard disk. When RAM runs low, virtual memory moves data from RAM to a space called a paging file. Moving data to and from the paging file frees up RAM so your computer can complete its work.

The more RAM your computer has, the faster your programs will generally run. If a lack of RAM is slowing your computer, you might be tempted to increase virtual memory to compensate. However, your computer can read data from RAM much more quickly than from a hard disk, so adding RAM is a better solution.

Virtual memory and error messages

If you receive error messages that warn of low virtual memory, you need to either add more RAM or increase the size of your paging file so that you can run the programs on your computer. Windows usually manages this automatically, but you can manually change the size of virtual memory if the default size isn't large enough for your needs. For more information, see Change the size of virtual memory.