Good Android phone with 2.3Ghz Quad-Core processor provides good performance and great system execution.

Performing the firmware upgrade for Sprint:

1. Download and save the HTC One for Sprint firmware upgrade to your PC.
2. Connect your device to your PC via the supplied USB cable.
3. If the device is not recognized by the PC, ensure you have HTC Sync Manager installed and then disconnect and reconnect the device from the USB cable.
4. Once the device is properly recognized on the PC, locate the Sprint firmware upgrade that you downloaded. Double-click on the file to launch the system update wizard.
5. Follow all of the system upgrade wizard instructions shown on your PC.
6. Once the upgrade is complete, click Finish in the Wizard and the device will reboot.
7. Once the device reboots, the initial setup wizard will appear.
8. Once the initial setup process is complete, the device is ready for use.

Note : If the firmware upgrade wizard fails to recognize the device, close the wizard and then follow the steps below:
· From a powered off state, hold VOLUME DOWN while powering on the device.
· Use the volume buttons to scroll to FASTBOOT and then press the POWER button to select it.
· Connect the device to the PC while in this state and attempt the firmware upgrade again.

To exit FASTBOOT manually, use the volume keys to navigate to REBOOT and press the POWER button to select it.

Flash Firmware via fastboot

-rename firmware to firmware.zip
-copy firmware.zip to your sdk folder
-boot into bootloader
-plug in usb
-select fastboot option (screen should say fastboot usb)
-type Fastboot oem rebootRUU
-when u see the black screen w/ HTC, type Fastboot flash zip firmware.zip
-when it's done, type Fastboot reboot

There is several different ways to do this, it depends on the flash file that you have.