Maybe it's as Inferno told, NSIS (NISIS.... CRISIS ? xD ) is telling this is not a place for you xD Have you checked if you have over 3 GB space on your HDD when downloading ? For a download of 1.3 GB...
You also need a temporary mempory which the PC use while downloading, activating, and the mod, once activated on the game, makes 3.8 GB on 4.1 GB counted the second way.