The "run with software rendering" option (if you used it from the Start - Programs menu) only applies to the current run of particleIllusion. So if you use software rendering, close particleIllusion, then run it again normally (not using the "run with software rendering" option) then it's not using software rendering.
You can switch particleIllusion to always use software rendering on the OpenGL page of the Preferences dialog. Uncheck the "use hardware acceleration" checkbox, then click OK to close all dialogs, close particleIllusion, then run it again.
I suggest you do this and if the "minidumps" still occur, please tell me in as much detail as you can what you are doing when they do happen.
I somehow think it could be the RAM. I increased to 2 GBs tonight. Also increased my page file to 6,114 mb. I'll give it a try and let you know tomorrow what happens and what I was doing, IF I get another mini-dump.
Right now, I'm FAPed (hughesnet satellite internet) until tomorrow night (24 hours) so it takes a while to load internet pages.