1. A method of updating a wireless device comprising: a wireless device receiving a notification indicating that an updated package is available for the wireless device, the update package comprising a plurality of versions of an update; the wireless device transmitting, in response to receipt of said notification, device-specific information to a server system, the device-specific information comprising compatibility information relating to the wireless device; the wireless device receiving data specifying a location of a version of the update from the server system, the version having been selected based on the compatibility information; and the wireless device using the received data to access said selected version of the update.