If you receive warnings that your virtual memory is low, you'll need to increase the minimum size of your paging file. Windows sets the initial minimum size of the paging file at the amount of random access memory (RAM) installed on your computer plus 300 megabytes (MB), and the maximum size at 3 times the amount of RAM installed on your computer. If you see warnings at these recommended levels, then increase the minimum and maximum sizes.
Open System by clicking the Start button , clicking Control Panel, clicking System and Maintenance, and then clicking System.
In the left pane, click Advanced system settings.
If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
On the Advanced tab, under Performance, click Settings.
Click the Advanced tab, and then, under Virtual memory, click Change.
Clear the Automatically manage paging file size for all drives check box.
Under Drive [Volume Label], click the drive that contains the paging file you want to change.
Click Custom size, type a new size in megabytes in the Initial size (MB) or Maximum size (MB) box, click Set, and then click OK.
Increases in size usually don't require a restart, but if you decrease the size, you'll need to restart your computer for the changes to take effect. We recommend that you don't disable or delete the paging file.