SonicBlade

I've stumbled over the Sins of a Solar empire demo recently and since I liked it a lot I am now considering purchasing the game via download (unfortunately the retail doesn't seem to have hit Europe yet). I'm sceptical as far as digital purchases are concerned, so I have a few questions. I've read that it is possible to back up the product - so far so good. What steps are necessary to reinstall the product from the backup on either the same or a different computer ? Is it possible to perf