Help with Lenovo K910 Vibe Z

Hi all,

First of all i want to introduce myself a little bit..
I am a Lenovo user for almost a year now.. And i am from The Netherlands..

Iam placing this topic, but i am not sure if it is in the right subform..

So i have a few questions related to the Vibe Z..

I bought it from China and it is a dual sim phone.. It came with Android 4.2.2

The issue i am facing is i cannot update it to example 4.4 Kitkat.. The moment i check for system update, settings get crashed..

It also came upt with the app SuperSU and google playstore.. I am not sure if it was already rooted..


I would like to root the phone and install an other ROM..

Can someone help me out with this?

I have searched on the forum,youtube, internet, but i could not fix it..

How can i unlock the bootloader?

So thats why i am placing this topic..