Is this XP?
To adjust Virtual Memory:
Rt. Click My Computer/Properties/Advanced/Performance/SettingsAdvanced/Virtual Memory
Try twice your RAM
If you really have 248 MB of RAM, (Probably 256 MB with 8MB used for video RAM) you would benefit greatly from installing more.

Yes hughv is correct 256 mb of ram is hardly enough to run windows these days. If you have dd2, it doesnt cost much to buy a couple 512 sticks. If you have sd ram try a new pc

Page memory size... what you need for a page file depends a bit upon what you do... whether you work with huge files or graphics manipulators.. and with a small RAM you need a relatively larger page file than if you had a large RAM so that it all adds up to a useful virtual memory size.Your error has several sources... here:
http://www.aumha.org/win5/a/xpvm.php

with only 248 megs of ram it wouldn't matter what you are trying to do you will get this error ,with such a small amount of ram ,and a windows default setting of virtual ram ,you are going to get this error message .anyway quick fix is adding more ram ,and I will assume its DDR SDRAM and not DDR2 ,and I will not suggest you buy a new computer but, definitely add some more ram at least another 512 stick.Im in Canada but ,i buy ddr sdram 512 for $23.00 canadian from here, http://www.bitsmore.com/ cheaper than a new computer ,maybe not as fast, but my 3 yr old computer does me just fine . ,