MAJOR UPDATE Found the problem responsible for most of the please reinstall game problems.
If you have ever installed The Earth Trilogy on your pc before steam this applies to you.
The Earth Trilogy fails to remove registry files that deal with the placement of the directory.
Use this guide to find them
Use regedit to examine the value of the following keys:
"OutputDir"="F:\Program Files\SSI\The Moon Project"
"DataPath"="F:\Program Files\SSI\The Moon Project/>;G:\game/>"
After you have found these keys right click and press Modify, copy paste the current directory for Earth/Moon/LostSouls and it should work.
For instance(S:\ProgramFiles\steamapps\common\Earth 2150 The Moon Project is what my Moon Project is under so you just add (S:\ProgramFiles\steamapps\common\Earth 2150 The Moon Project/>;F:\game/>) like so for the first entry and (S:\ProgramFiles\steamapps\common\Earth 2150 The Moon Project) for the second.
Basic problems include resolution problems which cause the game to crash at the research, and consturction center screens.
More Advanced problems would be the game crashing after creating a profile before the Skirmish, Multiplayer, or Campaign screens.
Lan Problems include not port forwarding and if your using hamachi I have a whole guide on how to use that, which is probably the best way to play a private match with your friends.
Fixes in the same order are
Resolution problems can be fixed by changing the resolution to 1680x1050x32 or lower, you can use OpenGL to if you get constant crashes like some users, although you will have to run the game at a lower resolution than 1680x1050x32.
The game crashing after creating a profile before the Skirmish, Multiplayer, or Campaign screens, is solved by turning off Data Execution Prevention (walkthrough in its ussage is herehttp://windows.microsoft.com/en-us/windows7/Change-Data-Execution-Prevention-settings?SignedIn=1
Finally running the multiplayer through tcp/directip means you will either have to port forward your router, or use hamachi. Port Forwarding is not reccomended because it is usually much harder to do for certain people, say you live in a dorm. Hamachi is a better option for private games and much easier to use. To use hamachi, download it from the internet create a profile and then create a network. As of now hamachi can only have 5 other computers on a network including the host machine. Whoever runs hosts the game just hosts the game through tcp/directip. From here is where most bugs are. Most people can see the game but can't join it but a few can't even see the game. To fix both issues use a program called forcebind ip gui which you can find on google. Once you have that program use it to force bind the unique ip that hamachi has given you to Earth/Moon/LostSouls's exe once done force bind ip gui should boot the game and you should be able to see the game and join it. The host does not need to use force bind ip gui.
Hopefully this can clear up some of the problems I keep see poping up.
Hope to see you in a game one day,