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When I connect my USB-to-RS232 ADAPTER on USB 2.0 port on Windows 7 (64-bit), I get:

Device driver software was not successfully installed

Prolific USB-to-Serial COMM Port (Failed)

On Device Manager Properties, Device Status is: This device cannot start. (Code 10)

When I update driver, message is: The best driver software for your device is already installed but device error is remaining. I also downloaded and installed driver from Prolific website but same result.

Checking chip version I get: OPEN COM PORT FAILED

What is actually wrong on accessing this device?

share|improve this question
From the link posted: "Please be warned that counterfeit (fake) PL-2303HX (Chip Rev A) USB to Serial Controller ICs using Prolific's trademark logo, brandname, and device drivers, were being sold in the China market. Counterfeit IC products show exactly the same outside chip markings but generally are of poor quality and causes Windows driver compatibility issues (Yellow Mark Error Code 10 in Device Manager). We issue this warning to all our customers and consumers to avoid confusion and false purchase." – Ƭᴇcʜιᴇ007 Mar 30 '14 at 17:43
Propably you 're right. – dempap Mar 30 '14 at 18:58

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