I suppose you want to reset the variables whenever the PC is rebooted, but not when the program is being rerun?
I think I would define all the variables that I intended to use at the beginning of the program. They could all be initialized to zero, or whatever you need. Put this list of variables within a loop that itself has a flag so that this initialization loop executes only once, the first time the program is run after a restart of the PC.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)