A digitally signed executable file for upgrading or restoring the phone from a Windows PC. 2. Why Use This Specific RUU? This RUU is essential for:

Stands for ROM Update Utility . This is a self-executing Windows application ( .exe ) used to flash stock factory firmware directly onto an HTC device from a computer.

To fully understand what this file does, we can break down its complex naming convention step-by-step:

Manually installing a system update when the Over-the-Air (OTA) method fails. Installation Prerequisites

4.0.3 – 4.0.4 (Ice Cream Sandwich, API 15)

This usually means your phone's bootloader is unlocked. Run fastboot oem lock in a command prompt before restarting the wizard.

If you are looking to restore your to its factory state or simply want the official Ice Cream Sandwich (ICS) experience for the Taiwan/Asia region, the official RUU is the most reliable method.

Flashing this RUU installs a specific combination of legacy software components onto the device: Android 4.0.3 (Ice Cream Sandwich) User Interface HTC Sense 3.6 Device Compatibility HTC EVO 3D GSM (PG86100 / X515m) Target Region Taiwan (CID: HTC__621) Radio Firmware 11.77.3504.00U_11.25.3504.06_M Kernel Version 3.0.x Linux Kernel Share public link