Open → Ports (COM & LPT) . You should see:

Right-click the Windows Start menu and select .

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Many counterfeit PL-2303 chips exist. Since Windows 8/10, Prolific has deliberately broken drivers for counterfeit chips. If your adapter is fake, the driver will install but show Error 10 (This device cannot start) or Code 28 .

This adapter originally came from the manufacturer MCT (Magic Control Technology Corporation), though many brands, including Belkin, have rebranded MCT's design for their own products (F5U109). It houses a Prolific PL2303 chipset, the heart of the adapter which handles the conversion between USB and serial signals.

To ensure compatibility, you should download the driver directly from the original manufacturer or reputable support sites: Magic Control Technology (MCT): The official MCT Download Page offers the latest drivers for the Prolific Tech:

If you have landed on this page, you are likely holding a (often labeled as "U232-P9") and struggling to get it working on a modern Windows 10 PC. You are not alone. The "U232 P9" is a common, budget-friendly USB-to-serial converter chipset, but its driver support for Windows 10 is notoriously problematic due to Microsoft's increasing security requirements for driver signatures.

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Check the box next to the Prolific/U232 driver update to permanently prevent Windows from downloading it. Troubleshooting Persistent Connection Issues

What is the or code showing in Device Manager?