A library of over 250,000 device drivers, firmware, BIOS and utilities for Windows. Microsoft-provided in-box driver (Usbser.sys) for your Communications and CDC Control device. In Windows 10, the driver has been rewritten by using the Kernel-Mode Driver Framework that improves.

Dec 21, 2020 • Filed to: USB Recovery • Proven solutions

Have you ever had difficulty connecting your devices to your computer using a Prolific USB to Serial adapter? If yes you are lucky to find this page, it will give you all the information need to fix an unresponsive Serial driver adapter. You may have noticed a yellow exclamation mark hovering over or beside the USB to Serial Driver when searching your Device Manager and if you have we can all agree that it signifies a prevailing problem.

Overview of the Error

If you are not able to connect your device to your PC using a USB to Serial adapter it may be that

• The USB driver is outdated
• The USB Driver is missing
• Or even a corrupted driver

While you can't be so sure what the exact problem is there are solutions you can adopt to fix the issue once and for all. Read on to find quick fixes to resolve the problem.

1# Fix Prolific USB to Serial Driver not Working

Solution: Roll your Prolific USB to Serial Driver back to an older version

Updating your drivers often work wonders for your system because it makes sure that it runs on the latest features that guarantee maximum functionality. Unfortunately updating your drivers can cause this kind of error especially if your latest update does not work too well with your hardware. Once you upgrade your PC to the latest Windows version your Prolific USB to Serial Driver also updates to the latest driver software and if the driver is not compatible with your Hardware issues may arise. To correct the error, you will have to download the driver again by following these steps.

• Right-click on your PC Start button and open Device Manager

• Double click LPT and COM ports then locate the Prolific USB to Serial Driver and right-click it so you can select Update Driver

• For driver software click My computer

• From My computer select 'Let me pick from a list of drivers available'

Elcometer Port Devices Drivers

• Choose an older version from the list then click Next

• The driver you selected will be installed automatically
• Once it has been downloaded reconnect the driver to see if it works.

2# Fix Prolific USB to Serial Driver 'Coder 10'

Driver issues reveal themselves in so many ways or through messages such as

• This device will not start (Code 10)
• There is no driver installed in this device
• The driver was not successfully installed

A code 10 error may arise because the chip you are using is not an original one. If you are using a fake, the manufacturer has a way of disabling it due to copy write infringement and the copy write takes effect once you download a recent update. To protect your PC from getting this code, you will have to make sure that your Windows 10 never updates a driver without approval. Updates come in the form of 64 bit and 32-bit drivers. Below we will show you how to work your way around the problem.

Window 64 bit Fix

To fix Windows 64 bit OS including Prolific USB to Serial Adapter, follow through these steps.

• Download 'PL2303_64bit_Installer.exe and Save
• Remove every USB to Serial adapter from your PC and double click the 'PL2303_64bit_installer.exe
• Follow the prompt by plugging in one USB to Serial adapter the click on Continue
• Reboot your PC to get Windows up and running

If you have followed these process through and you still see the same error go to your device manager

• Open the control panel and navigate to Device Manager
• From your control panel navigate to the System category and click the Hardware tab
• Scroll to the LPT/COM port and double click Prolific USB to Serial Comm Port
• Click Drivers in the Properties section
• The Driver you choose should read '3.3.2.102 with an appropriate date attached
• If the date is wrong then it means the wrong driver was installed
• Unplug the Serial adapter and run the steps again to install the correct driver

Window 32-bit

For Windows 32-bit OS systems follow these steps

• You will have to download the 'PL-2303_Driver_Installer.exe and save from Microsoft download link
• Run the program and eradicate the driver if you can
• Run the installer once more to install a correct driver

To Troubleshoot for error if your device still does not work

• Go to Control panel, enter System to access your Device Manager
• Scroll down to the LPT/ COM port then double click Prolific USB to Serial Comm Port
• Click Driver in the Windows Properties section
• The driver must be numbered as '2.0.2.8' and dates accordingly

If the driver was not installed, remove the Serial adapter then run 'PL2303_Driver_Installer.exe' again. Follow directions in Device Manager to download the correct driver

The three solutions listed in this article have proven to be quite helpful in fixing a Prolific USB to Serial driver not working on Windows 10. They may appear confusing at first but if you follow each step in detail you can resolve the issue.

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TCP/Com^®

Multi-function Serial <-> Ethernet Redirection Software

Multifunction serial to ethernet (and ethernet to serial) interface software. Easily access a serial device via a TCP/IP or UDP network or redirect Ethernet/IP data to real or “Virtual” RS232 serial ports. This allows you to use existing Windows-based serial RS232 communications software to send and receive data across any TCP/IP network.

TCP/Com software is extremely simple but powerful. It can be used to solve a wide variety of device interfacing and RS232 or TCP/IP conversion problems, such as the following:

• Turn a PC into a Serial Device Server (Terminal Server)
• Send or receive data over a TCP/IP port with any serial communications program
• Open COM ports located on another computer in your network as if they were local
• Use Ethernet network (or the Internet) as a giant serial RS232 cable (Serial Tunneling)
• Feed data from one physical RS232 port to multiple RS232 serial communications applications
• Map a TCP/IP port to a different TCP/IP port

Use TCP/Com as a Serial Device Server (Learn More)

Share serial devices over a network (or even the internet)

Use TCP/Com as a Virtual Serial Port Splitter Cable (Learn More)

Windows does not allow multiple programs to access the same COM port. Bypass this restriction by using TCP/Com to split a single COM port into multiple virtual COM ports. This allows all your serial communications programs to access the same data.

Intuitive Multi-Document Interface

In the TCP/Com window just select the com port number and the serial communications parameters for your serial device and enter an IP address and a socket number. Then activate! It's that easy! Com port data will appear at the IP address and data from an IP port will appear at a real or virtual com port.

Recent Updates

Version 9.0.0 (released August 2020) Updated Virtual COM Port drivers

Elcometer Port Devices Driver Updater

Version 7.0.4 (released June 2014) Fixed rare issue with 'Remote Pings' feature not functioning correctly.

Version 7.0.3 (released March 2014) now allows users to name individual session windows to better manage multiple connections. A bug fix that addresses the remote pings feature is also included.

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Version 7.0.2 minor bug fix

Version 7.0.0 Updated Virtual COM Port drivers