It's possible to log the installation this way:
- Open a command prompt, by typing C M D, then Enter on the Windows start area.
- Type this:
CD "C:\Program Files (x86)\Addon Manager" ( this, assuming you installed in the default location, if not, you must change it to where you installed it )
- then this:
Couatl_Updater2 /INSTALLMODE /LOG
This will start the installer. After it loads, try the installation again and, when it stops, exit and check if you have a file named LOG.TXT there. Just send it back as an attachment.