How to Increase Virtual Memory In Windows XP

Introduction
As the name implies, virtual memory is non-physical memory.

Windows uses virtual memory when it doesn't have enough "regular" physical memory to perform a task. When it does this, Windows uses your hard drive to store information that normally would be put into your Random Access Memory or RAM .
Virtual memory is simulated RAM. When you have used up all your physical memory, your computer will shift data to an empty space on the hard drive. The computer swaps data to the hard drive and back to your RAM as needed. If you don't have a lot of hard drive space left and you're experiencing lots of problems, lack of virtual memory may be why. When Windows runs out of memory (virtual and non-virtual), it just doesn't run all that well.
Why bother to add extra RAM to your computer when you can use hard drive space instead? Main reason - RAM is much faster. Whenever you're using a lot of virtual memory, you're slowing your computer down. The best work around is to get more physical memory. Minimum requirement for a computer with Windows XP as its operating system is 512MB and 1GB at least for Vista. RAM price has gone down nowadays and having a 1GB or 2GB for your computer is not that expensive anymore. The more physical memory the faster the processing of your computer will be and the more programs you can run simultaneously.
How to Increase Virtual Memory
If you find yourself running out of virtual memory, or keep getting messages telling you that you are, you might want to change from the default setting of “System managed size” or “No paging file” to a “Custom size” to increase your Virtual Memory to a more acceptable level using your computer’s control settings.
In Windows XP
1.Click on Start menu and right-click on My Computer and select Properties.
2.Select the Advanced Tab and select “Settings” under Performance option.
3.Under Performance options window, select the “Advanced” tab and click on “Change” under Virtual memory section located near the bottom of the window.
4.Under Virtual Memory, select “Custom size” under Paging file size for selected drive to manually set your computer Virtual Memory.
5.Enter the amount of Virtual Memory that you need to set in “Initial size” and “Maximum size”. You should choose the same amount for the initial size and maximum size. This will stop your CPU from constantly changing the paging file.
Tip: To stop your CPU from constantly changing the paging file, set the initial and maximum size to the same value. That is, 768MB for initial size and 768MB also for the maximum size. The value should be at least 1.5 times more than your physical RAM. For example, if you computer has 512MB of RAM, increase the virtual memory paging file to 1.5 * 512 = 768.
6.Click on Set.
When you are prompted to restart your computer, click Yes.

In Windows Vista
1.Click on Start menu and right-click on My Computer and select Properties and then click on the Advanced system settings.
2.Under System properties, select the “Advanced” tab and click on “Settings” under Performance section.
3.Under Performance options window, select the “Advanced” tab and click on “Change” under Virtual memory section located near the bottom of the window.
Note: By default, Vista is set to “Automatically manage paging file size for all drives”. Uncheck this option and select Custom size to manually set the Virtual Memory for drive C.
4.Under Virtual Memory, select “Custom size” under Paging file size for selected drive to manually set your computer Virtual Memory.
5.Enter the amount of Virtual Memory that you need to set in “Initial size” and “Maximum size”. You should choose the same amount for the initial size and maximum size. This will stop your CPU from constantly changing the paging file.
Tip: To stop your CPU from constantly changing the paging file, set the initial and maximum size to the same value. That is, 1500MB for initial size and 1500MB also for the maximum size. The value should be at least 1.5 times more than your physical RAM. For example, if you computer has 1GB of RAM, increase the virtual memory paging file to 1.5 * 1000 = 1500.
6.Click on Set.
When you are prompted to restart your computer, click Yes.
Tips and Warning
Play around with gradual increases until you are satisfied with your system performance.
Do no lower your Virtual Memory settings below the minimum allowed. This might cause system crashes and slowdowns.
Check on “Recommended” Virtual Memory settings under “Total paging file size for all drives” at the bottom of the window.