Are you not understanding simple english? Its NOT downloading.
I really feel the need to chime in here -the thing is 2.5 GB... what do you expect?
The solution would be to pay the man, so that he can afford to get a proper hosting solution. Of course optimizing the assets for size wouldn't be a bad Idea too, but that megaupload site really is a bad way of doing things.
@Etherium-Apex : If you want help with that, get in touch.
Edit: It seems it's hugely browser dependant if that download works. I've tested several, and megaupload seems only to recognize Chrome, and otherwise demands you download their app. Chrome works, but only if your browser-cache allows for that. It also asks for permission to store "files on your device", which - if you block the request - naturally stops the download.
While you really shouldn't blame the dev for your own computer-illiteracy, I agree that megaupload might not be the most user-friendly option here.