Windows XP is an example of a typical operating system that has virtual memory. Windows has an intelligent virtual memory manager that uses a default setting to help Windows allocate hard drive space for virtual memory as needed. For most circumstances, this should meet your needs, but you may want to manually configure virtual memory, especially if you have more than one physical hard drive or speed-critical applications.
To adjust your virtual memory:
Click Start and open the Control Panel.Double-click on System. The system dialog window will open.
Click on the Performance tab and then click on the Virtual Memory button.
Click on the option that says Let me specify my own virtual memory settings. This will make the options below that statement become active.
Click on the drop-down list beside Hard disk: to select the hard drive that you wish to configure virtual memory for. Remember that a good rule of thumb is to equally split virtual memory between the physical hard disks you have.
In the Minimum: and Maximum: box, enter 3x the amount of physical memory you have.For example, if your system has 1024MB (or 1 GB) of DDR RAM, enter 3072 into both boxes.When Windows is allowed to manage the paging file on it's own, it is constantly adjusting the size, decreasing your system's performance.These changes will set the paging file to it's maximum recommended size permanently.This also prevents the paging file from becoming fragmented.
Click Set to put the new settings into effect, then click OK and restart your computer to finish.
The amount of hard drive space you allocate for virtual memory is important. If you allocate too little, you will get "Out of Memory" errors. If you find that you need to keep increasing the size of the virtual memory, you probably are also finding that your system is sluggish and accesses the hard drive constantly. In that case, you should consider buying more RAM to keep the ratio between RAM and virtual memory about 3:1. Some applications enjoy having lots of virtual memory space but do not access it very much. In that case, large paging files work well.
Another factor in the performance of virtual memory is the location of the pagefile. If your system has multiple physical hard drives (not multiple drive letters, but actual drives), you can spread the work among them by making smaller pagefiles on each drive. This simple modification will significantly speed up any system that makes heavy use of virtual memory.