IF you want to root your SGS2 GT-I9100 following jelly bean 4.1.2 official firmware upgrade then check out “How to Root Galaxy S2 (GT-I9100) having Android 4.1.2 official firmware“
In January 2013, Samsung finally released much awaited Jelly bean 4.1.2 official firmware for the Samsung Galaxy S2. Initially in January, the firmware was released only for Spain and China. Since then, the update has been released in many more countries and in all likelihood you should be able to install it via Kies.
If you do not have Kies installed on your computer, you can download it here.
It is important to be aware of the fact that since the Android 4.1.2 Jelly Bean is an official firmware build, installing it will remove the root access on the device. Users will be required to root the Galaxy S2 once again. For instructions on how to root your device, following JB 4.1.2 upgrade, click here.
IF you want to check if the official JB 4.1.2 firmware for SGS2 for your country/carrier has been released or not, you can check it on sammobile. If it is released you can connect your phone to computer and via Kies you can download and install the update.
However, for the countries where the official firmware is not available, or those who are unable to download it via Kies, you can download it from here. Below are the things to do before you proceed with the installation.
1)Backup all your data from samsung galaxy s2 GT-I9100
2) Ensure that Galaxy S2 drivers are installed on your computer (If it is not, your phone wouldn’t get connected to your computer)
3)Enable USB debugging – Settings > Applications > Development > USB debugging (for Android 2.3 phones) or Settings > Developer options > USB debugging (for Android 4.0 phones)
4)Your phone should have atleast 80% battery life
5)This installation is intended only for Samsung Galaxy S2 (GT-I9100) and hence, users should check and confirm their model number before proceeding.
Simple steps for installation of the firmware
1) Extract the file which has firmware and Odin included.
2) Switch off the device and put in in download mode. To do this, press and hold the Volume Down and Home buttons while pressing the Power button until the Samsung Galaxy logo appears on the screen.
3) Open the Odin and connect your phone(SGS2) to the computer using USB data cable.
4) If your Phone is connected correctly, then you would see ID:COM sections turns yellow confirming proper connection with your phone.
5) In Odin, click PDA and select *.tar.md5 file
6) Click START which will then install the Firmware on your phone.
Once the installation is over, phone will restart. You will see the upgradation process on the screen. Congrats! you have successfully installed the latest JB 4.1.2 firmware on your phone.
As mentioned earlier, installing this firmware will remove the root access. If you want to root your device (GT-I9100), Click here
If you found this helpful or if you have any queries please leave a comment.