Virtual memory minimum too low

I'm running windows 2000 professional, and every time I boot up I recieve a message that reads as follows: "Virtual memory minimum too low, your system is low on virtual memory.Windows is increasing the size of your virtual memory paging file.Duringthis process, memory requests for some applications may be denied." I have 845MB of free disk space and I have more than the recommended paging file size needed. How can I make the message go away?