Once you fix the COM port handle, follow best practices to avoid a relapse:
QFIL cannot open a handle if the device isn't properly recognized by Windows. qfil failed to open com port handle
Sometimes, generic drivers don't work. You need the official drivers specifically designed for flashing tools. Once you fix the COM port handle, follow
The "Failed to open COM port handle" error in typically occurs because the software cannot establish a clean connection with your device's communication port . This is often due to improper driver installation, incorrect device mode (EDL), or another process using the port. Common Causes incorrect device mode (EDL)
Before giving up, rule out hardware: