When all of your computer's real physical memory (RAM) is in use, Windows will try to create virtual memory by grabbing a chunk of hard drive space and treating it like real memory. Your software can't tell the difference between real and virtual memory, but you might because virtual memory access is much slower, due to the hard drive activity it requires.

If you encounter the low virtual memory error message, then you have used the maximum amount of real plus virtual memory that is supported on your system. Sometimes programs that crash or ones that are poorly designed will not return their working memory space to the operating system when they're done using it. Other programs that need a large amount of memory to run may fail because Windows cannot "see" the available memory. In most cases, a shutdown and restart will resolve this problem.

To increase Virtual Memory:

In Windows XP

1.Click Start, and then click Control Panel.

2.Click Performance and Maintenance, and then click System.

3.On the Advanced tab, under Performance, click Settings.

4.On the Advanced tab, under Virtual memory, click Change.

5.Under Drive [Volume Label], click the drive that contains the paging file that you want to change.

6.Under Paging file size for selected drive, click to Custom size check box. You can enter the amount of memory you would like to reserve for Virtual memory by entering the initial and maximum size.

7.Click Set.

When you are prompted to restart the computer, click Yes.

• The value should be at least 1.5 times more than your physical RAM. If your computer has 512MB of RAM increase the virtual memory paging file to 1.5*512= 768

In Vista

1. Click Start button Picture of the Start button.

2. Click Control Panel.

3. Choose System and Maintenance and then click System.

4. In the left pane, click Advanced system settings.

5.On the Advanced tab, under Performance, click Settings.

6. Click the Advanced tab, and then, under Virtual memory, choose Change.

7. Click Custom to change the Initial size (MB) and Maximum size.

• The value should be at least 1.5 times more than your physical RAM. If your computer has 512MB of RAM increase the virtual memory paging file to 1.5*512= 768