Updates to the World of Warcraft: Wrath of the Lich King take the form of automatically-delivered patches. When an update is made available, it will be delivered to your computer when you next launch World of Warcraft: Wrath of the Lich King and connect to a server. It can take between seconds and hours to download a patch, depending on the size of the patch. Patches come with patch text notes detailing the changes made for that version.
Patching is normally automatic; you do not need to do anything special to receive a patch. Patching is also not optional; you must have the most current version in order to play on the World of Warcraft servers. If you have problems with the patching process, please contact Technical Support.