Originally Answered: Microsoft Word is giving me an error messege: "insufficient memory or disk space"?
Usually running out of virtual memory means that you are running too many applications at the same time for your system or one of them is attempting to use too much memory.
Increasing virtual memory is one way of compensating for lack of RAM. However, it's optimum should be set at 1.5 times the amount of RAM on your computer. Virtual memory can be increased, but it comes with a risk if you increase it too much as it can eventually lead to hard drive damage.
To increase VM on Windows XP (should be in similar locations for other versions) look in Control Panel: System, Advanced, Performance Settings, Advanced, Virtual Memory.
You can see if your computer can handle more RAM at http://www.crucial.com/index.asp
It's important to note that everything takes RAM. Not only security products (such as active anti-spyware, anti-virus and firewall) eat up memory but your operating system, active browser windows, running applications (such as Word, Gaming, Messenger, Photoshop, etc) and malware all compete for system resources. The presence of Malware (viruses, spyware, etc) will particularly eat up your system resources so you may want to run your resident security products such as antispyware and antivirus applications to ensure that your system is clean.
(Note: Virtual memory is not the same as hard drive size)