Thecus N4100PRO User Manual page 83

Type http://<Thecus_NAS>:631/printers/usb-printer in the box, where
<Thecus_NAS_IP> is the IP address of the N4100PRO. Click Next.
6. Select or install a printer and then press OK.
If your printer model is not listed, please contact your printer manufacturer
for help.
7. Windows will attempt to connect to the printer.
8. You can choose to set this printer as the default printer by checking the Set
as the default printer box. Click Next to continue.
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