This error occurs as many computer retailers keep the page file small because the majority of people use their computers for internet browsing etc. If you are suddenly going to start doing complex simulations, then the computer needs to do a little more and thus requires more memory.
The first thing to try is to make sure you don't have any other memory intensive applications running.
If not, increasing the page file is one solution and will probably solve the issue.
Caveat: do not increase the page file unless you know the Windows implications(we advise you ask your IT administrator to assist with this procedure)
The best solution is to have more RAM installed.
IES-VE Minimum Spec
• 20GB Hard Drive
• 1152 x 864 screen resolution
• Dedicated OpenGL-compliant graphics card
• 2Ghz+ Intel Pentium / AMD Athlon CPU
• 2Gb RAM
To increase your paging file have a look here: http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/sysdm_advancd_perform_change_vmpagefile.mspx?mfr=true