Hi. My name is Ivan, and I am an Independent Assessor. I'd be more than happy to assist you. I'm so sorry that you are experiencing this issue. Don't worry, I'll do everything I can to help you.

It is most likely a driver issue.

Sometimes newer drivers generate some incompatibility, so the best thing to do is try using an older version of driver.

• Go to device manager
• Right-click on the CH340 device
• Select Properties -> Driver -> Roll back driver

You can install it manually by downloading it from the device manufacturer.

for more info.

https://www.youtube.com/watch?app=desktop&v...

NOTE: This is not a Microsoft site, but it appears to provide accurate and reliable information. Be wary of ads that may advertise products that are often classified as PUPs (potentially unwanted products). Research any product advertised on the site before you decide to download and install it.

Hello, I'm Louie, and I'm happy to help you today. Hope you're doing well and safe there. I'm sorry that you're having trouble with your USB ports.

I would suggest you to try the methods provided below:

Method 1 - Check Power Management Settings

1. Right-click on the Start menu button and select Device Manager.
2. Expand Universal Serial Bus controllers
3. Look for the first USB Root Hub. In some computers, it could be just one. Right-click on it and select Properties.
4. Go to Power Management tab. Here, unmark the box beside Allow the computer to turn off this device to save power. Click on OK.
5. Repeat Step 3 and Step 4 for other USB Root Hub devices under Universal Serial Bus controllers.

Method 2 - Check Power Supply

1. Unplug your laptop’s power supply, along with the charger plug.
2. Now, restart the laptop.
3. Reconnect the USB device to the USB port of your laptop.
4. Plug charger and power supply back on your laptop.

Method 3 - Uninstall Drivers

1. Right-click on the Start menu button and select Device Manager.
2. Expand Universal Bus Controllers. Here, right-click on the USB Root Hub select Uninstall device.
3. Repeat the above step for remaining USB Root Hub.
4. Restart your computer.

After performing the restart, the Windows will recognize USB Root Hubs as new device and will install its drivers automatically.

Method 4 - Update Drivers

1. Right-click on the Start menu button and select Device Manager.
2. Expand Universal Bus Controllers. Here, right-click on the USB Root Hub select Update driver.
3. Now click on Search automatically for updated driver software. This will download and install the updated drivers for USB Root Hub on your computer.
4. Repeat the above two steps for remaining USB Root Hub.
5. Restart your computer.

Method 5 - Turn Off Fast Startup

1. Right-click on the Start menu button and select Power Options.
2. Under Related Settings, click on Additional power settings.
3. On the left side of the window, click on Choose what the power button does.
4. Now, select Change settings that are currently unavailable. This will let you change the shutdown settings.
5. Under Shutdown settings, unmark the box beside Turn on fast startup (recommended). And click on Save changes.
6. Restart your computer.

Method 6 - Disable USB Selective Suspend Setting

1. Right-click on the Start menu button and select Power Options.
2. Under Related Settings, click on Additional power settings.
3. Now, go to Change plan settings of your selected plan.
4. Select Change advanced power settings.
5. Look for USB Settings and expand it. Here, change the USB selective suspend setting to Disabled. Now click on OK.

Method 7 - Troubleshoot the issue

1. Go to Cortana and type Troubleshoot. Select the same from results.
2. Click on Hardware and Devices.
3. The Windows will check for issues. When done, click on Apply Repair Automatically or Apply this Fix, whichever appears.
4. Restart your computer.

Hope this helps and looking forward for good results.

Kind regards,

Louie

Hello Freestone Mitchell and welcome to the Microsoft Community!

According to your feedback, you are experiencing a problem with the USB to Serial connection.

For a solution to this issue, you can refer to the following options

Option 1: Use a compatible driver:

Try to download a compatible driver from another manufacturer.

For example, the drivers provided by FTDI are usually more compatible!

You can visit the official website of FTDI to download and install the driver for Windows 11.

Method 2: Use Windows built-in drivers:

Sometimes, the driver that comes with Windows 11 may be more compatible.

Try updating the driver in Device Manager, select “Browse my computer for driver software” and then select “Let me download the driver from my computer”.

Then select “Let me choose from a list of available drivers on my computer”.

Method 3: Contact the device manufacturer:

If none of the above methods work, we recommend contacting your device manufacturer to

Ask if there is a driver or solution for Windows 11.

We hope you find the above information helpful!

Kirito|Microsoft Community Support Specialist

Hi Lisa

I am Dave, I will help you with this.

1

Check the support page for your USB Serial Adapter to see if they provide Windows 11 drivers for that device.

2

If not and you do want to uninstall Windows 11, how long has it been since you upgraded to 11, is that 10 days or less?

If you upgraded within the last 10 days, open the Settings App, then go to System - Recovery, and in the 'Go Back' section, you can roll back to Windows 10.

If it has been more than 10 days since you upgraded, then the only way to go back to Windows 10 would be to backup all your personal files, then clean install Windows 10 from a bootable USB.

Hi, Rick Page1

Welcome to the Microsoft Community.

 If your USB to RS232 serial adapter with a Prolific chipset stopped working after a system update and you have tried various troubleshooting steps without success, here are some additional steps you can take to try and resolve the issue:

1. Check Device Manager:
   • Press Windows key + X and select "Device Manager."
   • Look for any devices with a yellow exclamation mark or under "Other devices" that may indicate a problem with the adapter.
   • Right-click on the problematic device and select "Update driver" to see if Windows can find a compatible driver.
2. Uninstall and Reinstall Driver:
   • Uninstall the current driver for the USB to RS232 adapter.
   • Disconnect the adapter, restart your computer, and then reconnect the adapter to reinstall the driver automatically.
3. Download Latest Driver: Visit the Prolific website or the manufacturer's website for the latest driver specifically designed for your adapter model and the updated operating system version.
4. Test on Another Computer: To ensure the issue is not with the USB to RS232 adapter itself, test it on another computer to see if it works correctly. If none of these steps resolve the issue, you may need to contact the manufacturer for further assistance or consider using a different adapter that is compatible with the updated system.

Best Regards

Martin | Microsoft Community Support Specialist

Same as hblin94.  No USB Serial Converter is listed.