There is a difference between UK versions and US versions on alot of games. The difference is mainly due to the US have wicked crazy censorship laws that the UK doesn't,, namely nudity. As far as Ship Sim goes however there isn't a difference in the actual game, just the box it comes in as far as I can tell. I myself have the UK version and as you can see I'm in the US.. runs perfectly fine and no problems,, plus yes you do need to make sure you back-up your copy of Ship Sim onto a back-up drive and/or disk just in case along with the CD Key that you will get in your e-mail.