How do you fix the never ending loop with Itunes authorization process??

Question

Every time I try to Sync my Iphone, an itunes popup shows up claiming that my computer is no longer authorized for the apps on my phone. On the pop up it gives three options to choose from: "Cancel", "Authorize", and "Don't Authorize". If I choose authorize, it asks me to put in my apple ID and password. Now right here confuses me because when that pops up, it show's a very old email that hasn't been used with itunes in atleast over a year (most likely longer).On an offside note, with my phone I understand a bit of why the email popups with my Iphone because I used to use the email until I got my own apple ID. But now when I try to Sync my girlfriends ipod, which has never come into contact with the email, it shows the same email. Anyway, I change the email to my current one and type in my password and click on "Authorize". Then comes the final pop up telling me "This computer is already authorized. Includin this one, you have authorized one computer out of your available 5." and then gives me the option "OK". I click OK and and the process repeats itself.
Here is a picture of the first popup.
I'm new to this so I don't really know if I need to blur anything out but this is it.
This is the second popup.This first pictures shows what it looks like at first and the second is me putting in my information.
Then the third popup after I click "Authorize"
and of course after this it repeats itself.
I have tried authorizing the computer under the itunes store tab but then it says its already authorized. I don't know how to fix this and it's been a pain for over a month. I heard someone else in my family had the same problem and it just randomly went away after certain amount of time, which I don't get. Any help is gladly accepted.
Also Merry Christmas

Answer 1

A few more details....
Go to Control Panel > Add or Remove Programs (Win XP) or Programs and Features (later)
Remove all of these items in the following order:
iTunes
Apple Software Update
Apple Mobile Device Support (if this won't uninstall move on to the next item)
Bonjour
Apple Application Support
Reboot, download iTunes, then reinstall, either using an account with administrative rights, or right-clicking the downloaded installer and selecting Run as Administrator.
The uninstall and reinstall process will preserve your iTunes library and settings, but ideally you would back up the library and your other important personal documents and data on a regular basis. See this user tip for a suggested technique.
Please note:
Some users may need to follow all the steps in whichever of the following support documents applies to their system. These include some additional manual file and folder deletions not mentioned above.
HT1925: Removing and Reinstalling iTunes for Windows XP
HT1923: Removing and reinstalling iTunes for Windows Vista, Windows 7, or Windows 8
tt2