Virtual memory allows the system to use hard disk space to store information normally stored in RAM. Windows 7 and Windows Vista manage virtual memory by using a paging file. You specify the minimum and maximum size of this file. If the size is different from the default in Windows Vista, applications may return errors. However, some applications may require a non-default size for the paging file. Change the size only if other applications aren't adversely affected.
2. Choose Start > Control Panel.
3. Click System and Security (Windows 7), or System and Maintenance (Windows Vista), and then click System.
4. In the Computer Name, Domain, and Workgroup Setting section, click Change Settings.
5. Click the Advanced tab, and then click Settings in the Performance area.
6. Click the Advanced tab, and then click Change in the Virtual Memory area.
7. Deselect the Automatically Manage Paging File Size for All Drives option.
8. From the Drive list, select a hard-disk partition that has free space equal to at least three times the amount of the computer's installed RAM. To determine the amount of space available on a hard-disk partition, click the drive letter; the amount of space available appears in the Paging File Size For Selected Drive area.
9. Click Custom Size.
10. In the Initial Size box, enter a value equal to one and a half times the amount of the computer's installed RAM.
11. In the Maximum Size box, enter a value equal to twice the amount of the Initial Size value.
12. Click Set, and then click OK to close the Virtual Memory dialog box.
13. Click OK to close the Performance Options dialog box, and then click OK to close the System Properties dialog box.