Crashing Problems in Demo

Hi, this seems like a game I’d be interested in, though I’m worried that my computer may have issues with since the Demo did not work.
I can play the demo, but it crashes at seemingly random points with the basic error message appearing (I can’t remember what it is exactly, it basically says ‘This program has crashed, Windows is now looking for a solution’). Is this problem fixed in the actual version?
Also, if these crashes can be fixed, I’d like to purchase the game for my mam too, is it possible to have downloads from different computers? I have no experience with paying for software online.