Seems like there are two Mega download links(one encrypted and one not), TW posted the encrypted here. Go to his blog and try the Mediafire or...
Try this fix:
post #2752 by schidddy on page #111
I'm a noob so don't ask me for help. PM the poster.
I see you have a GTX 680. Why aren't you using Nvidia's Shadowplay? It's free for Nvidia cards and you'd get much better performance.