Confused Mounted image issues

[Access Denied]

So I'm trying to play Star Trek: Armada 2 because nostalgia. Since I don't have an optical drive on this computer (Who does these days?) I've downloaded an ISO, well it's a Disc Image File but it's fine.

I'm running Windows 10, so I mounted the image using the built in software, installed the game and eagerly started it up. All fine until I get to the menu and click single player. At which point it tells me to insert the game disc and won't let me do anything else. Can't alt-tab out, Windows key doesn't have any effect. Have to exit the game.

Help?

 

[caLLous]

When you say "downloaded an ISO", was there a crack to apply after installation? Sounds like a copy protection issue (or, at least that it's expecting to find an actual disc). Search for "Star Trek Armada II no cd" and go from there.