USB SERIAL CH340 CHIPSET NOT WORKING AFTER Windows 10 KB5046613 and KB5046542 UPDATE

Question

Greetings

After installing this update, the Windows 10 KB5046613 and KB5046542 UPDATE, the usb serial adapter, used to connect a scale, didn´t work anymore

The device appears as an valid com3 port, but, when the software tries to communicate, returns that the device it's not available.

I have to roolback the windows to a previous date backup, and everything works fine.

Even installing a usb serial adapter with prolific 32 chipset, fails after restart.

the wch.cn driver, from 30-01-2019 works fine, but the new one, it's not working

After retore windows to a previous point, the driver backs to 2019 version, and everything works fine.

the adapter used is like this Amazon.com: Ozeau Black USB to RS-232 Serial Cable Standard Adapter Converter for PC : Electronics

Answer 1

Dear Victor Rondón,

Thank you for reaching out regarding the issue with your USB serial CH340 chipset not functioning properly after installing the Windows 10 KB5046613 and KB5046542 updates.

Let’s work on troubleshooting and resolving this problem.

1. Check the Current Driver Version

• Connect the USB Serial Adapter to your computer.
• Open Device Manager (Windows + X > Device Manager).
• Expand the Ports (COM & LPT) section.
• Right-click the CH340 device, select Properties, and navigate to the Driver tab.
• Check the driver version and date.
• If the driver is newer than the 2019 version, proceed to roll back or reinstall the compatible version.

2. Roll Back to the 2019 Driver Version

• In Device Manager, right-click the CH340 device and select Properties.
• Go to the Driver tab and click Roll Back Driver (if available).
• Restart your computer and test the device again.
• If the rollback option is unavailable, proceed with the manual installation of the 2019 driver.

3. Manually Reinstall the 2019 WCH Driver

• Download the compatible driver from wch.cn’s website or your device manufacturer’s site.
• Disconnect the USB serial adapter.
• In Device Manager, uninstall the current driver:
  • Right-click the CH340 device.
  • Select Uninstall Device and check Delete the driver software for this device (if prompted).
• Restart your computer.
• Install the 2019 driver manually by running the installer or using the Update Driver option in Device Manager.
• Reconnect the USB adapter and test functionality.

4. Block Windows from Updating the Driver Automatically

• Press Windows + R, type gpedit.msc, and press Enter.
• Navigate to Computer Configuration > Administrative Templates > System > Device Installation > Device Installation Restrictions.
• Enable the policy "Prevent installation of devices that match any of these device IDs".
• Add your device’s hardware ID to the list:
  • Right-click the CH340 device in Device Manager.
  • Go to Properties > Details and select Hardware Ids from the dropdown.
  • Copy and paste the hardware ID into the group policy configuration.
• Apply the policy and restart your computer.

5. Disable Automatic Driver Updates

1. Press Win + R, type sysdm.cpl, and press Enter.
2. Go to the Hardware tab and click Device Installation Settings.
3. Choose No (your device might not work as expected) and save the changes.

6. Install Driver in Compatibility Mode:

1. Download the stable driver from wch.cn here.
2. Right-click on the driver installer file and select Properties.
3. Go to the Compatibility tab, check Run this program in compatibility mode for and choose Windows 7 or Windows 8 from the list.
4. Click Apply and run the installer.

If the issue persists, please reach out to the manufacturer of the USB Serial Adapter or visit their support forums for any known issues or updated drivers that may not be listed publicly.

Best Regards,

Martin | Microsoft Community Support Specialist

Answer 2

What a crazy workaround! Why not just providing an update to fix the problem?

Microsoft develops in impressive track record of rolling out updates that brick people's computers.

Maybe it's time to rethink your update strategy.

Answer 3

Over 200 bill validators units in various points of sale that used the CH340 driver were affected by this update. They are currently non-functional and without any hope to remedy the situation. This is not the first time when an Windows update can destroy a business. Two years ago we faced the same problem when after an update none of the Star Micronics thermal printers worked anymore. Going to over 200 points of sale and applying the workaround offered by Martin seems to be the way out of the market for us.

Answer 4

I don't think that Microsoft will fix the problem, having considered that it's due to a counterfeit chip mounted on our controller. Try downloading an old driver from https://www.wch-ic.com/downloads/ch341ser\_zip.html.

Probably it's old enough to not recognise counterfeit chips

Answer 5

comment faire