USB Serial Adapter Driver: Diagnosing the Common Errors
A serial adapter either creates a port or it does not, and when it does not the error code tells you almost everything. Most failures are driver related rather than hardware related.
Quick Answer
Install the driver for the actual chipset, not the brand on the housing. Code 28 means no driver. Code 10 often means a counterfeit chip that the current driver refuses. Port conflicts and lingering installations are cleared through the device list. Keep a copy of the installer for each chipset you use, because site internet access cannot be relied on.
Error Codes and Meaning
| Code or symptom | Meaning | Fix |
|---|---|---|
| Code 28 | No driver installed | Install the chipset driver |
| Code 10 | Device cannot start | Usually a counterfeit chip rejected by the driver; try the chip maker older driver or replace the adapter |
| Code 43 | Device reported a problem | Replug, try another port, check for power issues |
| Unknown device | Enumeration failed | Replug, reboot, then test elsewhere |
| Port appears twice | Duplicate installation | Remove all entries and reconnect |
| Port works then stops | Power management or cable fault | Disable selective suspend, replace the cable |
Counterfeit Chips
Cheap adapters sometimes contain cloned chips that older drivers accepted and current drivers reject outright. The result is a device that worked for years and then failed after an update. There is no reliable software fix. The practical options are the older driver for that chip family, if it is still available and acceptable, or replacing the adapter with one that uses genuine silicon.
Clean Installation Procedure
- Uninstall any existing driver for that chipset.
- Remove hidden device entries from the device list.
- Reboot before installing again.
- Install the current driver from the chip maker.
- Connect the adapter and confirm the port appears.
Platform Notes
Windows
Driver signing is enforced, so unsigned old drivers may not install on current versions.
macOS
Third party system extensions need approval in Privacy and Security before they load.
Linux
Kernel drivers cover most chipsets. Check the kernel log after plugging in to confirm the port was created.
Real-World Applications
- Recovering a production machine where a working adapter suddenly stops.
- Deploying adapters across a fleet with a standard installer.
- Diagnosing a replacement laptop that lacks the right driver.
- Preventing repeat outages by standardising on one chipset.
Related Guides
For port configuration, read USB to COM port adapter. For macOS specifics, see USB to serial adapter on Mac. For chipset advice, start with USB serial adapter.
FAQ
Why did my adapter stop working after an update?
The new driver no longer supports the chip, which is typical of counterfeit parts.
Can I use a generic driver instead?
Rarely. More specific drivers work better. The chip maker driver is the correct choice.
Do I need to reboot after installing?
Often yes. Rebooting also clears stale device entries.
How do I know which chipset I have?
Check the device identifier in the system device list and match it to the chip maker driver list.