The important stuff first:
Does the crash occur after a certain length of time using Blender, or does it occur after a certain event, like duplicating an object?
The number in the upper right corner of the Blender interface screen shows how much RAM your scene uses - what is that number?
How many vertices does your duplicated object have, and how many times are you duplicating it? You may be exceeding the vertex/face limit; Blender can handle about 4 million polygons.
I hope this helps.
The following is just some tech stuff that will probably not help you with your problem, but if you’re curious:
***Stop: 0X0000005A (0X 00000001, 0X00211724, 0X0000000001, 0X82046320)
0x5a is the Windows NT/2k stop code for Critical Service Failed, which is not well documented. Stop codes are fairly straightforward, though - Windows spits them out on a blue screen when the kernel cannot recover from “catastrophic” (Microsoft actually used that word) errors. The parameters - the numbers in parentheses - for different stop codes are all different, and they are not necessarily memory locations.
I’m just curious: How much RAM do you have that there are 300 megs left when Blender crashes?