Why can't iTunes download and install iOS 7?

I can't update to iOS 7 with just my iPhone. I need Wi-Fi. So I've tired downloading and installing 5 times already in iTunes. Each time it tells me it's gonna take 25-26 hours. But when it gets to 21 hours left, a small page would appear saying "An unknown error has occurred (9006)." It's getting me frustrated. Is there something I'm doing wrong while updating to iOS 7?

Samsung S4 or Iphone 5s! WHICH ONE?

So tomorrow i'm getting a new phone and right now its s4 or iphone 5s? I LOVE ANDROIDS customization but i love iphone true simplicity and power! I don't know which one to go with?! Which One Do You Think Is Best

Is there a collage for instavideos?

I have android, S4, and I was wondering if there's a collage for instavideos? I see people post it but I'm pretty sure they have iPhones. Is there one for android?

Need an iphone 4s or greater so badly?

Hi… I'm short of money and my father really doesnot believe in buying us expensive phones as he all of our lifes wants to concentrate on our studies although i got 87% marks in my 10 grade… So how can i get an iphone…

Will the server block my iPhone?

I've got my iPhone from the US, but I don't live there. Somebody told me that if I try to upgrade to iOS 7, the server might block my iPhone and it might just become a useless toy. I have never upgraded it before. I have no problem downloading Apps or using iTunes, and all of that. I'm just worried if it will block my iPhone. Please help me.
P.S: Do not give stupid answers like "Go and live in the States".
Thanks in Advance. Any help will be appreciated!