What is ClockworkMod?
ClockWorkMod recovery allows you to perform several advanced recovery, restoration, installation and maintenance operations on your Android device, that aren’t possible with the stock recovery.
Before flashing ClockWork Mod recovery, please make sure that you already Unlocked Bootloader.
Turn on your phone, plug it in your computer using a USB data cable and connect it in USB debugging method (Settings > Developer options > check USB debugging)
2. Flash recovery
In the folder you just extracted, run the file Desire C.exe. In the right top corner box select ClockWork Mod and click Flash Recovery button, press OK in the window that appears.
There should appear a Command prompt window, and your Device should automatically reboot into Bootloader mode. If this didn’t happen and the command prompt says: < waiting for device > then check this on how to fix this error.
If the device is in the Bootloader mode, close the command prompt, this should open another Command prompt that will finally flash recovery in some seconds. When it finishes close it. On your device using Volume keys choose Reboot and using Power key confirm.