Check out the below URL please:
SAMSUNG
okey AT&T Samsung Galaxy Note owner, this is indeed a good news that at last AT&T has released the Jelly Bean 4.1.2 upgrade. of course, AT&T always late and careless about their smartphone OS upgrade matter. Although many smartphone like AT&T's Samsung Galaxy SII, Samsung Galaxy SII Skyrocket and Samsung Galaxy Note was bricked while upgrading through KIES, yet not AT&T released this type of OS upgrade via OTA and Kies both ways.
the main Samsung US webpage for Samsung JB update yet not updated, because there is JB update announced in that page for AT&T Samsung Galaxy SII Skyrocket or AT&T Samsung Galaxy Note. the link is below:
SAMSUNG
But now Note user can directly follow the below webpage for their JB upgrade on Note -
SAMSUNG
Before start update it will be perfect if you format your device properly (factory reset including internal USB storage).
On your windows pc, just uninstall Kies and Samsung usb driver. I suggest, restart your pc after every installation or uninstall please.
Microsoft .NET framework 3.5 or higher must be installed (you can have it from Microsoft website), whatever theme you are using, it'll better if you set classic Windows Theme(after JB upgrade you can change that). after latest Kies is installed properly and restarting your pc, disable your antivirus (or internet security software), windows firewall and windows defender.
Now you can open Kies and connect your Note via USB cable and after your device has detected properly then you can easily go for Jelly Bean upgrade step by step.
hope the success of all AT&T Samsung Galaxy Note user about Jelly Bean upgrade.
Thanks in Advance