How do you reset the microcontroller once you no longer have access to the programming software?
If by “Reset” you mean “Reload the default software”, I think you could get a copy of the free “IFI Loader” and use it to reload a copy of the (already compiled) default software.
Try using the tools described in this web page
https://jvex-robotics.dev.java.net/ToolChainSetup.html
Blake
I do not have any of the programming stuff. Why can’t there just be a very small default button?
Do you have the orange cable to connect your computer to the Vex? If not, is there a school in your area that you can borrow/use on?
If you have the orange cable you can download the IFI loader and the default .hex code from this site.
Ack, I bet you wish you’d programmed it with the default code before you got rid of the programming kit 
(or how ever you did it before).
I think your best bet is to find someone who could do it for you. I’m in the silicon valley area, you? I’d be happy to reset it for you.
Update: I see you are in NY, which is not quite very close to CA 
The offer still stands via mail, but surely someone near you might be able to help you too.
Alex, while it would be a great feature to have, it would be an expensive one. IFI would need to create a new motherboard with additional memory on it to hold the program, and they would need to engineer a way to make it auto replace the old program when reset. (or they could make a toggle between original program and user downloaded) The processor might not be able to handle it, and they’d have to upgrade it. The memory/new processor/new mobo would increase the price of the controller by a good $50 I’m guessing.