When you encounter the Firmware update pop up, it would be in your best interest to defer the update to another time if you plan on using the board within the next hour or so. There are two options on how to deploy the update.
1) Wait until the end of the day and turn your board off. Wait ten seconds then turn it back on. Wait for the Firmware screen to pop up. Begin the update so when you return the following day the board is completely up to date.
2) Place a Freshdesk ticket with IT. State the time that you want the update deployed. Make sure the board is on and IT will remotely deploy the update.