Name: HTC One M9 Driver
Author: HTC

Question 1

Install fails or rolls back?

Accepted Answer

Run the HTC USB driver installer as administrator, close HTC Sync Manager, and temporarily disable driver signature enforcement if Windows blocks the unsigned HTC One M9 driver. Reboot before retrying.

Question 2

Device not detected?

Accepted Answer

Use the original USB cable and a rear USB 2.0 port. On the M9, set USB connection to MTP or PTP; for ADB, enable Developer options and USB debugging, then accept the RSA prompt.

Question 3

Version conflicts or yellow warning?

Accepted Answer

Uninstall older HTC Sync Manager and previous HTC/ADB drivers. In Device Manager, right-click the M9 entry, uninstall and delete the driver, reboot, then install the current driver.