It is common issue with dongles and very difficult if not impossible to sort out. The best to use PC with integrated Bluetooth. First of all you connect printer with USB cable and allow windows to install it. It will be ready for wired printing.
Now you can go to Control panel and Add Device (not Add Printer but Add Device). It will install device with printer icon but it is not a printer yet.Go to properties, hardware and note COM port number on which it is installed. Only now you go to Control Panel, Add printer, Choose Local-not Bluetooth, create COM port with the same number you noted if it is not available yet and install drivers by choosing ZD420, add pairing code when requested and here your misery should end. You can read through thousands of forums about this issue online - maybe some solutions will help you, maybe not. I tried myself two dongles on two computers and failed to install properly but on laptop with build in Bluetooth it went like through butter. Data transfer via Bluetooth is much slower than via Network cable.