Virtual Memory Low Warning

using Windows XP:

Click Start / Control Panel / Performance and Maintenance / System / Advanced tab 
Under Performance click the Settings button.
Click the Advanced tab.
Under Virtual Memory, click the Change button.
Under Paging file size for selected drive,put a tick next to Custom size:.

The minimum should be 1.5 times your memory size. The maximum should be three times your memory. If you continue to have problems, raise the maximum. Keep raising it until you no longer get the message.
Then click the Set button.

Or, the best solution, you could increase the amount of RAM your system has, by buying more, since the hard drive is much slower than RAM.