Since my game box has a manual but no disc, I got the GOG version today, as I really needed to play this again. There's a problem installing under Vista, though, in that the game only seems to run under the account the game was installed under. Which, in turn, makes me a very unhappy person.
I discovered this by sheer luck. To reproduce:
a) have an admin on your box (let's say "hero")
b) have a regular user on your box (this one's "loser")
c) log on as hero and install the game [installer runs with admin token]
d) log off
e) log on as loser and start the game [regularly or with admin token]
What happens is basically zilch: there's no sign the game was started. I didn't bother tracing with process explorer/monitor or the like.
After uninstalling I ran through the same procedure as above, with the same result. For some weird reason I tried the following
a) make "loser" an admin
b) log on as loser and install the game
c) start the game
Result: works.
I repeated process 1 with "loser" already being an admin before even installing by "hero", with the same results (only runs when previously installed by admin-loser). This makes no sense at all, requires elevated privileges Redmont finally (albeit in a horribly bad way, as usual) tries to avoid, and is completely non-intuitive and impossible to find out, except by the abovementioned sheer luck.
Meh. I'd love to see this fixed ;-/
P.S.: Ah, I forgot to remind everybody how hilariously great this game is :)

not sure if I understand the question, but I'll say this;
turn off UAC.

Not an option on that particular machine for reasons beyond the scope of this forum. Besides, UAC on/off is not the same as running with an admin account or not. You still run with or without admin token, except that wit UAC disabled admin accounts receive it automatically.

Hi,
I don't know if this will work, but have you tried installing the game under the "loser" account just in a different directory than the game on the "hero" account?
It might not work but it just might be a workaround for your particular problem.

Besides JudasIscariot's advice, what keeps you from installing the game under the administrator account and then, when starting it from the normal user use the Run as Administrator option? It should work.

There's more to this problem than mere user-rights:
Installed the game using a user-account with administrator privileges.
Logged on as another user, also with administrator privileges.
Game would *not* run - so there's something connected to the user account that installs the game.
I then followed frilled's example and came to pretty much the same conclusion - with only one thing to add - if I grant "loser" admin rights, logon/install the game, revoke "loser"'s admin rights, the game still works (when logged on as "loser"). Not much of a solution, but at least a feasible (if somewhat fiddly) workaround.

Is this a general GOG installer problem, or is it specific to Giants? That might give a bit more of a hint on where to look. Have you tried to do the same with any other GOG games?

If I'm not mistaken, this happens simply because Giants requires some reg keys to be present and these are stored in HKEY_CURRENT_USER.
Try the following:
1. Log in with the user who installed Giants
2. Open RegEdit (requires root access).
3. Go to HKEY_CURRENT_USER/Software/PlanetMoon
4. Select PlanetMoon key
5. File/Export to a reg file.
6. Put the reg file somewhere where your other user can access it.
7. Login with your other account.
8. Double click the reg file to import it. (requires root access).
9. Try launching the game

I know this is an old post and all, but I would like to state that this solution fixed the exact same issue for me in Windows 7, 64 bit.

I would be happy to see this post marked as a solution