The Prolific PL2303 is a USB-to-Serial chipset used in adapters and cables that allow Windows computers to communicate with equipment using a serial/COM connection. Windows 11 can install compatible PL2303 drivers automatically, but manual installation may be necessary when the adapter appears with a yellow warning icon or reports a driver error.
Prolific currently provides Windows 11 WHQL drivers for several PL2303 families. Its current Windows installer supports Windows 11 64-bit and includes drivers for newer PL2303G and PL2303HXD-family hardware. (Prolific)
Before You Begin
You will need:
- A Windows 11 computer
- A PL2303 USB-to-Serial adapter or cable
- An available USB port
- Internet access if using Windows Update
- The appropriate Prolific driver package (for older drivers look here)
Important: Not every PL2303 chip works with current Windows 11 drivers. Older PL2303H, PL2303HX Rev A and PL2303X/XA chips are discontinued and do not have Windows 8 or newer driver support according to Prolific's documentation. Older cables can therefore produce errors even when the driver was installed correctly.
Method 1: Let Windows 11 Install the Driver Automatically
This is the easiest method and should be tried first.
Step 1 — Connect the Adapter
Plug the PL2303 USB-to-Serial adapter into an available USB port on your Windows 11 computer.
Give Windows several seconds to detect the device.
Step 2 — Open Device Manager
Right-click the Start button and select Device Manager.
Alternatively, press:
Windows + X → Device Manager
Step 3 — Find the Adapter
Expand:
Ports (COM & LPT)
You may see an entry similar to:
Prolific USB-to-Serial Comm Port (COM3)
The COM number can be different on your computer.
If the device appears under Other devices with a yellow warning icon, Windows has detected the hardware but does not currently have a working driver.
Step 4 — Update the Driver
Right-click the Prolific device and select:
Update driver → Search automatically for drivers
Windows will search its available driver sources and install a compatible driver if one is available.
Step 5 — Check the COM Port
After installation, return to:
Device Manager → Ports (COM & LPT)
The adapter should now appear with a COM number.
For example:
Prolific USB-to-Serial Comm Port (COM3)
Your serial software should use this COM number when connecting to the attached equipment.
Method 2: Install the Prolific Driver Manually
If Windows does not automatically install the correct driver, download the driver package from Prolific.
Prolific's current Windows installer is version 4.9.0.0, released March 6, 2026. The package includes Windows 11 64-bit WHQL drivers for PL2303G and PL2303HXD-family devices and supports Windows 11 versions including 21H1, 22H2, 23H2, 24H2 and 25H2.
Prolific official PL2303 driver page
Step 1 — Download the Driver
Download the appropriate Windows Driver Installer Setup Program from Prolific.
Save the downloaded file somewhere easy to find, such as your Downloads folder.
Step 2 — Extract the Package
If the driver is supplied as a ZIP file:
- Right-click the ZIP file.
- Select Extract All.
- Select Extract.
- Open the newly extracted folder.
If the download is already an .exe installer, extraction may not be necessary.
Step 3 — Run the Installer
Right-click the installer and select:
Run as administrator
Follow the installation wizard.
Allow Windows to install the Prolific driver when prompted.
Step 4 — Restart Windows
Restart the computer after installation.
This ensures that Windows loads the newly installed driver correctly.
Step 5 — Connect the Adapter
After Windows starts, connect the PL2303 adapter.
Open:
Device Manager → Ports (COM & LPT)
Verify that the adapter is listed.
How to Verify the Driver Installation
Once the driver is installed, Device Manager should show the adapter without a yellow warning icon.
Right-click the device and select:
Properties → Driver
You can check:
- Driver Provider
- Driver Date
- Driver Version
- Digital Signer
The provider should normally identify Prolific for a genuine Prolific driver.
You can also select:
Properties → General
A properly functioning device should report:
This device is working properly.
How to Find the PL2303 Chip Version
The exact PL2303 chipset matters because different generations have different driver support.
Prolific's current driver packages include a CheckChipVersion utility that can help identify supported PL2303 hardware. (Prolific)
This is particularly useful when an adapter is several years old or Windows reports that the device isn't supported.
Fix: "PL2303TA Does Not Support Windows 11"
One of the most common problems with older Prolific adapters is the PL2303TA chipset.
You may see a message similar to:
PL2303TA DO NOT SUPPORT WINDOWS 11 OR LATER
This is not necessarily an installation failure. It can mean that the particular chipset revision isn't supported by the current Windows 11 driver.
Prolific's older documentation identifies several discontinued PL2303 generations that don't receive modern Windows driver support.
What to do
First, identify the exact chipset in the adapter.
If it is an unsupported legacy device, installing the newest driver may not fix it.
You have several practical choices:
- Use a driver version specifically compatible with that older chipset.
- Use the adapter with an older supported Windows installation.
- Replace the adapter with a newer PL2303-based model.
- Consider an adapter using another USB-to-Serial chipset if compatibility is critical.
Avoid downloading random modified drivers from unknown websites simply to bypass Windows driver restrictions.
Fix: Code 10 — "This Device Cannot Start"
A Code 10 error is commonly associated with incompatible PL2303 hardware/driver combinations.
Step 1 — Open Device Manager
Go to:
Device Manager → Ports (COM & LPT)
Step 2 — Open Properties
Right-click the Prolific device and select:
Properties → General
Check the error message.
Step 3 — Remove the Existing Driver
Right-click the device and select:
Uninstall device
If Windows provides the option:
Attempt to remove the driver for this device
select it.
Then click Uninstall.
Step 4 — Restart Windows
Restart the computer.
Step 5 — Install the Correct Driver
Install the appropriate Prolific driver for the chipset and Windows 11 version.
Then reconnect the adapter.
Fix: The Adapter Doesn't Appear Under Ports
If the adapter isn't listed under Ports (COM & LPT):
- Disconnect the adapter.
- Restart Windows.
- Connect it to another USB port.
- Open Device Manager.
- Select Action → Scan for hardware changes.
- Check Other devices and Universal Serial Bus controllers.
If absolutely nothing changes when the adapter is connected, the problem could be the USB port, cable, adapter hardware, or chipset rather than the driver.
Fix: Windows Keeps Installing the Wrong Driver
Windows Update can automatically obtain compatible Prolific drivers. Prolific specifically documents automatic driver delivery through Windows Update for supported PL2303 hardware.
This can become problematic with older adapters that require a particular driver version.
If the adapter worked previously but stopped after a Windows update:
- Open Device Manager.
- Right-click the Prolific adapter.
- Select Properties.
- Open the Driver tab.
- Check the current driver version.
- If Roll Back Driver is available, you can try it.
- Restart Windows and test the adapter again.
For unsupported legacy hardware, however, a driver rollback is not guaranteed to remain functional after future Windows updates.
How to Determine the COM Port
After successful installation:
Device Manager → Ports (COM & LPT)
Look for:
Prolific USB-to-Serial Comm Port (COMx)
For example:
Prolific USB-to-Serial Comm Port (COM4)
The COM4 portion is the port number.
Enter that same COM number into the software you're using to communicate with the serial device.
Test the Serial Connection
Once the driver is working, you can test communication with the attached serial equipment using its appropriate software.
Depending on the hardware, you may need to configure:
- COM port
- Baud rate
- Data bits
- Parity
- Stop bits
- Flow control
These settings are determined by the equipment being connected, not by the PL2303 driver itself.
PL2303 Driver Compatibility
The important distinction is that "PL2303" is a family of chipsets, not one single hardware revision.
Newer PL2303 variants have current Windows 11 support, while some older variants do not. Prolific's current Windows package specifically lists support for newer PL2303G and PL2303HXD-family devices, while its documentation identifies older discontinued chips that lack modern Windows support.
Therefore, if a driver installation fails, don't immediately assume the downloaded driver is bad. First determine which PL2303 revision is actually inside the USB-to-Serial adapter.
Quick Troubleshooting Checklist
| Problem | Recommended action |
|---|---|
| Adapter not detected | Try another USB port |
| Yellow warning icon | Install/update the Prolific driver |
| Code 10 | Check the chipset and driver compatibility |
| PL2303TA unsupported message | Identify the chipset and use a compatible solution |
| No COM port | Check Device Manager after reconnecting |
| COM port changes | Windows may have assigned a different COM number |
| Worked before Windows update | Check the installed driver version and available rollback |
| Serial software cannot connect | Verify COM port and serial communication settings |
| Very old adapter | Check whether the chipset is discontinued |
Final Verification
A successful installation should leave you with:
Device Manager → Ports (COM & LPT) → Prolific USB-to-Serial Comm Port (COMx)
There should be no yellow warning icon, and the device's Properties page should report that it is working properly.
For the most reliable Windows 11 installation, use the official Prolific driver that matches the actual PL2303 chipset rather than assuming every PL2303 adapter can use the same driver.
