At turn 263 my Motbw campaign has finished because my computer refuses to keep running it so it's "hi ho, hi ho and Back to genesis we go, we go"!

Did you try increasing your virtual memory?
Did you try lowering the turbo settings in Bios or set it to 'fail safe'? (amazing how often this gets games working).

Thanks m8 but my system runs fine… The issue is the code behind the game leaks like a sib and can't handle all the units.

To be clear, I got motbw for free with my genesis and don't feel cheated that it is unstable.

Oh yea, i had that problem come up in Galactic Civilizations and Dreadlords until they finally fixed it.

I had to run some other random program in the background so that when the memory ran out, i could CNTRL ALT DEL then close the background program and recover enough memory to go back and save the game.

CleanMem (free version) perhaps?

Not encountered a similar problem (yet...) but saving/closing/restarting/loading tends to work with most leaky software.