1. Click 'Start' and select 'Control Panel.' Click 'System and Security' in Windows 7 or 'System and Maintenance' in Vista.
2. Click on 'System' and select 'Advanced system settings' in the left-hand column. Select the 'Advanced' tab and then click on 'Settings' under the 'Performance' section. Select the 'Advanced' tab and click the 'Change' button in the 'Virtual memory' section.

3. Click to remove the check mark next to 'Automatically manage paging file size for all drives.' Click to highlight the drive that you want to change, which is typically the 'C' drive.
4. Click the radio button next to 'Custom size.' Type the new minimum amount for virtual memory in the 'Initial size' field. This should be 300 megabytes more than the amount of RAM in your computer.
5. Type the new maximum amount for virtual memory in the 'Maximum size' field, which should be three times the amount of memory in the system. Click the 'Set' button and click on 'OK.'