Set it to 1.5x the amount of RAM in the system (in your case 1.5GB is the size you need to increase the page file to)
How to manually change the size of the virtual memory paging file
You must be logged on as an administrator or as a member of the administrator’s group to complete this procedure. If your computer is connected to a network, network policy settings may prevent you from completing this procedure.
To manually change the size of virtual memory, follow these steps: Click Start, click Run, type sysdm.cpl in the Open box, and then press ENTER.
Click the Advanced tab, and then under Performance click Settings.
Click the Advanced tab, and then under Virtual memory click Change.
Under Drive [Volume Label], click the drive that contains the paging file that you want to change.
Under Paging file size for selected drive, click Custom size, type a new paging file size in megabytes (MB) in the Initial size (MB) or Maximum size (MB) box, and then click Set.
Click OK to close the dialog box and apply changes.
Note After you change the size of the paging file, you may be prompted to restart Windows. If you are prompted to restart, the changes will not take effect until Windows is restarted