If you are intending to print labels via a Zebra GK420d it is worth downloading the latest drivers from the Zebra site rather than relying on the drivers that Windows provides which can sometimes be unreliable. You can obtain the latest drivers from here.

https://www.zebra.com/gb/en/support-downloads/printer-software/printer-setup-utilities.html

Just hit the download link for

Zebra Setup Utilities for Windows