Find COM Ports On Windows

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2. Find COM Ports On Windows

Computer SetupReviewed 2026-06-27

Summary

For USB serial machines and USB-to-RS-485 adapters on Windows, the connection usually appears as a COM port. If Rostoc cannot find it, check Device Manager for the port and any driver warning.

Steps

1. Plug in the machine or USB-to-serial adapter.
2. Open Windows Device Manager.
3. Look under "Ports (COM & LPT)" for the new COM port.
4. If there is a yellow warning icon, install the driver from the machine or adapter manufacturer.
5. Reopen Rostoc and select the COM port assigned to the device.