How come I can't download Firefox from Internet Explorer?

[Sam]

My videos on Youtube and other websites weren't loading so I decided to uninstall Firefox (My preferred browser) and reinstall it on Internet explorer. However I couldn't, one of the problems would be that it can't finish downloading the Firefox setup wizard and I got that fixed but now when Firefox itself is downloading from the setup wizard the download bar continuously loads at the end of the loading bar and doesn't ever continue on to the installing part of the process. I've tried everything, I've checked forums and common questions asked on Mozilla's website as long as some similar questions asked on here but nothing works. I'll put a link to a screen shot of the problem and what this looks like, however instead of the bar freezing as it appears in the screenshot obviously it still looks like it's loading. This problem also occurs when trying to download Google Chrome.

http://gyazo.com/20cdc4f617b05de0cce1b00684e508fd

After a while of waiting the bar also restarts the download randomly. Help would be greatly appreciated and I would be so thankful I've spent too much time trying to fix this and I'm tired of Internet Explorer and my videos don't even load on this either so I'm clueless.
Hey thanks for the offline installer and and tips on how to manage my browsers better hopefully I don't make this mistake again!