If you have a device that is registered to a screen network, but you need to register it elsewhere, you will need to de-register
If you know which screen network they're on, simply login to your account to and de-register the device so you can use it again.
To know more about de-registering a device, click HERE.
Once de-registered, you will have to go through device set up again and enter your new screen network email and password. To know more, click HERE.
For instructions on how to find your screen network's email and password, click HERE.
If you don't know which screen network it belongs to, please contact your account administrator.