Troubleshooting Virtual Memory
Virtual memory (VM) is auxiliary storage on a computer's hard disk which the operating system uses when the random access memory (RAM) is full. It used for all normal computer applications. The longer your computer is running, the more cluttered the memory becomes. If your PC's memory capacity is exceeded, you may get a message informing you that your virtual memory is too low.
For temporary fixes to this problem, the best solution is to reboot the system. The longer your computer is running, the more cluttered the memory becomes. Cleaning the hard drive will also help. To do this, run the Disk Cleanup program and then Disk Defragmenter. These programs can be found from the Start menu by highlighting All Programs and selecting Accessories, then System Tools on the dropdown menu. For more persistent problems you will need to either add more RAM so that you are not using any VM, or else change the paging file size (PFS) of the virtual memory. Paging file size is the amount of memory reserved for virtual memory.
To change the PFS, the first thing you will need to do is determine the right level of virtual memory for your computer. Setting the VM too high will actually slow down the computer. The ideal setting is about 150% of your PC's total RAM. For instance, if the RAM is 512 MB, then you will want to set the VM to 768 MB. If you're not sure about how much RAM your PC has, go to Control Panel from the Start menu, and then select Performance and Maintenance, then click System. The amount of RAM is shown next to the type and speed of your processor on the General tab of the System Properties window. The amount shown will be slightly less than the actual amount. For instance, if it says 496 MB, then the actual amount is 512 MB.
Once you have determined the appropriate amount of virtual memory, click on the Advanced tab, or navigate to the System icon of the Control Panel if you haven't done so already. Click the Settings button under Performance, then click on the Advanced tab. On the Advanced tab, click the Change button under Virtual Memory. Select the drive you want to change from the list if it is anything other than the default. (This will normally be the C: drive with no other options.) Click on the Custom Size check box under Paging File Size and enter the initial and maximum amounts that you would like to reserve for the virtual memory. Entering the same amount will give your computer a consistent operating speed, but this is not necessary. When you are finished, click OK and restart the computer.
If the virtual memory message continues you may have a virtual memory leak which will require additional steps to fix. To find the program responsible for a virtual memory leak, use Task Manager (ctrl+shift+esc or ctrl+alt+del). Click on the Processes tab and look for executable files that are using too much memory under the Mem Usage column. Then uninstall the selected program and delete the executable or disable it in the Windows registry. Changes to the Windows registry like this should always be made with caution.
For those not technically inclined, or for those who want to improve their computer performance overall, it is suggested that you download PC Health Advisor. It will scan your computer for any issues it has and fix the problems it has detected.