Skew - woot!
Noppita - try deleting or renaming your QGROUNDCONTROL.ini file. It will be in your Users folder, under your user name, in AppData\QGroundControl folder. Easiest might be to do a search for it.
If that doesn't work, see what it says in the error message if you expand the View Details link, and c/p that info here. You could also try downloading the zip file again, using the direct link.
Thanks,
-Max