Screenshot of Device Manager showing "USB-SERIAL CH340 (COM4)" ✅ 4. Troubleshooting FAQ (for support page) Q: Does Windows 11 automatically install CH340 drivers? A: Sometimes, but often incorrectly. Manual installation is more reliable.
A: Microsoft tightened driver signing for Windows 11. You must temporarily disable enforcement or use the latest signed driver from WCH (v3.8+ is signed). ch340 driver windows 11
A: Check Tools → Port → correct COM. Also try pressing reset button on board right before upload starts. ch340 driver windows 11