Open Start -> Run (or press Windows-Key and R simultaneously). Type in
%appdata%
and press Enter or click "OK". This should open an Windows Explorer window for the "AppData\Roaming" folder within your user folder, which is normally hidden. Navigate to Avorion.
Is there a File called ".startupCrashDetection"? If so, try to delete it and then try to start Avorion again.
Does it start now or does it crash again?