Mass Effect - Installation Woes - If All Else Fails...
BioWare seems to be having some issues with the Mass Effect installer and also with Vista's UAC security feature.
There is a way to install the game manually if you can't get the game installed for some reason (installer error, saferun, etc).
You will need:
1) access to the contents of the data directory (either off CD, download, temp files, etc)
2) WinRar or 7zip or any tool that can extract .rar files.
1) Create a folder on your system somewhere. Default for the installer is "C:\Program Files\Mass Effect\" or a games folder.
2) Open each .rar file in the utility chosen (WinRar for e.g.)
3) Extract each .rar file into this folder. If you are using an English build, you won't need to extract any .rar file that has a different language code (_es, _fr, _de, _it, etc)
4) After extracting all files, your folder should look like this:
5) Run the MassEffectLauncher.exe and quit immediately.
6) Run the "Mass Effect (tm)_code.exe" from the data folder. Enter your CD Key, click next, it will exit out.
7) Run the Launcher again, hit "Config". under the "Repair" tab, you can re-create your shortcuts if running XP. If running Vista, I'm sorry, you can't add the game to the Game Explorer in these instructions.
9) Quit back to the launcher.
10) Play! (everything should work nicely now)
I hope that helps some people!
...and if you've installed successfully but it crashes when you run it in Vista, you may need to disable UAC for the first run:
Windows Vista users with UAC (User Access Control) enabled may experience a crash to desktop when running Mass Effect after installation.
The solution to this problem is to disable UAC, run Mass Effect PC once and then enable UAC on your Windows Vista Control Panel. Once the procedure has been completed, you will not have to repeat the it unless Windows Vista is reinstalled. [...]
Source: Voodoo Extreme
Information aboutMass Effect
SP/MP: Single + MP