Just bought the expansion for AOE III called "The Warchiefs". Went to install it and it said I didn't have AOE3 installed for either the current user or all users. Which is curious, because I was just playing it a few minutes earlier.
Did a little searching and found the problem. It seems that the Warchiefs installer does a check for the Microsoft Games\Age of Empires III folder in your Start menu and if it doesn't find it won't install. I don't know about you guys, but I NEVER keep programs in their default Start Menu location. A pet peeve of mine is people that have 50 million folders with programs scattered everywhere. So of course I moved the shortcuts to another folder. I just think it is pretty dumb of MS to not only assume that everyone kept their shortcuts in the default location but to refuse to install if it is not so? That just boggles my mind.... -- Brian