Site won't work without "www."

I’ve spent hours on this problem. I have a multisite “http://www.youngleek.com” and “http://www.youngleek.com/store“. If I drop the “www.” from any url, like “youngleek.com/store” or “youngleek.com/wp-admin” it all redirects to “http://www.youngleek.com“.

I’m researched this and I guess it has something to do with the htaccess file. I’ve found ways to redirct www to non-www and I found a way to redirect “youngleek.com” to “www.youngleek.com/store” but I couldn’t figure out how to make “youngleek.com/store” to go to the right place. Even if I could find a solution for that particular link, I’d like to make it so every link without www redirects to the appropriate place. How the heck do I do that? I checked everything I did through godaddy and the site was set up as “youngleek.com” and not “www.youngleek.com”. If the solution requires reinstalling wordpress, I’m totally okay with that.

Any advice?
…Please?