By default, the bootloader ZTE X990 is locked on the phone. This is done so that the novice user does not make a fatal error while editing the device kernel and does not turn the phone into a brick.
Advantages of Rooting your ZTE X990
The ability to install unofficial firmware and mods
You can unlock the bootloader and then enable Root Access
Ability to modify system files
You can install your own ROMs.
Disadvantages of Rooting your ZTE X990
Rooting your Android Phone will void your warranty.
Be unavailable to update
Risk of 'bricking' a phone.
Virus Attack.
How to root ZTE X990 with Computer (via Windows Phone Internals)
Before starting the rooting process, follow these steps.
1. Backup Your Device.
2. Make sure your battery is charged to 90%.
3. Just to be safe, reboot your device.