Virtual memory enables you to use disk space to extend the amount of available RAM on a system by writing RAM to disks through a process called paging. In Windows 8 allocates virtual memory in an amount at least as large as the total physical memory installed on the computer. Computers with 4 GB or less of RAM, you should set the maximum size to at least twice the total physical memory.
1. Right click on computer option and click properties.
2. Open the Advance System settings Options dialog box.
3. On Advance option tab, click on performance setting option.
4. In Performance Option, Click Advance
5. On the Advanced tab, Click Change to display the Virtual Memory dialog box
6. In virtual Memory option
Drive [Volume Label] and Paging File Size (MB) Shows how virtual memory is currently configured on the system.
Total Paging File Size For All Drives Provides a recommended size for virtual RAM on the system and tells you the amount currently allocated.
7. By default, Windows 8 manages the paging file size for all drives. If you want to manually configure virtual memory, clear the Automatically Manage Paging File Size For All Drives check box.
8. Select Custom Size, and then enter an initial size and a maximum size.
9. If you updated the settings for a paging file that is currently in use, you’ll see a prompt explaining that you need to restart the system for the changes to take effect. click OK.