Download Root Tool From Here
First of all you have to download and install adb drivers in your PC. Link given above.
Download the root package and extract it to desktop. or anywhere you like.
Now turn on USB Debugging in your QMobile Noir Z8 by going into Settings-> Developer Options-> and enable usb debugging.
Connect your phone with PC via USB cable.
Double-click on root z8......exe file and press any key on your pc.How to root Noir Z8
If you have drivers installed, your QMobile Noir Z8 will Reboot into custom recovery. This does not install the cwm recovery because the recovery image is not fully working.
When your phone boots into cwm recovery, press any key on your pc to continue.
Now your phone will start to show some weird colors but you don’t have to worry, its notmal. Just Press Volume down once and then press power button. Your phone will reboot and it should now be rooted.
Congratulations! You have successfully rooted your QMobile Noir Z8. You can check