For best performance and proper memory handling the Windows page file should be set to 'System managed size'. Here are the steps to check these settings using Windows 7. Windows XP and Vista use similar menus.
Open the Windows Control Panel.
Double click the System icon, the following window will appear:
Click Advanced system settings.
Click on the Advanced tab.
Click the Settings button under Performance then click the Advanced Tab on this new window. Then under Virtual memory click 'Change'.
Click the hard drive (Volume label) that you wish to apply these settings to then choose 'System managed size' then click Set.
You can also tick 'Automatically manage paging file size for all drives'
Once done click OK or Apply for each window to exit and save settings.
Reboot your computer.