[HELP] My 4GB Xbox 360 E Won't Download My Xbox Live Profile

I setup my brand new 4GB Xbox 360 E last night, and when I tried to download the Xbox Live profile I created on my desktop PC a few months ago, my Xbox 360 kept giving me random error codes. I googled them all and followed ALL of the instructions, to no avail.

Am I going to have to reformat my Xbox 360 and start from scratch? Please tell me there's a simpler fix that doesn't involve me having to start over again.

Verify that all email addresses and passwords are a match. Log in via pc at www.xbox.com and look at your settings to be sure that you have the correct information.