Recent content by Usama Javed1

guys i rooted my One when it was on 4.1.2 firmware. I bought it from O2. running software number is 1.29.206.16. the kernel version atm is 3.4.10-gf97ab24. I installed the TWRP. I want to unroot the phone and go back to stock ROM and update to 4.2.2. Is there any RUU or any way to go back to...