Here's what you can do. I feel like putting it in steps
1.) Make sure you have the download under "My Orders" on http://www.shipsim.com
2.) Make sure your key works and the download can be run without errors
3.) To install on a new computer, make sure the game is not on the previous computer(I think there's something about installing the game on multiple computers)
4.) Go back to "My Orders" and click on the blue links.
I have included a picture of the links that I'm talking about. They have been circled
Scott