How to Break WEP Encryption

Breaking any encryption involves knowing a few things. First, you have to know that there is an encryption scheme. Secondly, you must know how encryption works. Breaking any code manually is near impossible; luckily, you can break the WEP encryption if you use a packet-sniffing program.

1 - Use Linux. Windows cannot sniff WEP packets, but you can use a bootable CD of Linux.

1. 2 - Get a packet-sniffing program. Backtrack is a commonly-used option. Download the iso image and burn it on a bootable CD/DVD.
2. 
   3
   Boot Linux and Backtrack. Use your bootable CD/DVDs.
   • Note that this operating system is not required to be installed on hard drive. That means whenever you shutdown the Backtrack, all your data will be lost.
3. 
   4
   Select a start-up option. The following Backtrack screen will show after booting. Change the option with the up and down arrow keys and select one. This tutorial will use the first option.
4. 
   5
   Load the graphical interface via command base. In this option, Backtrack is started on command base. Type command: startx to continue.
5. 
   6
   Click on terminal button at the bottom left. It'll be the fifth option.
6. 
   7
   Wait for the Linux command terminal to open.
7. 
   8
   View your WLAN type. Enter the following command: "airmon-ng" (without quotes). You should see something like wlan0 beneath Interface.
8. 
   9
   Get all the required information for the access point. Enter the following command: "airodump-ng wlan0" (without quotes). You should get three things:
   • BSSID
   • Channel
   • ESSID (AP Name)
   • Here's what the tutorial case turned up:
     • BSSID 00:17:3F:76:36:6E
     • Channel number 1
     • ESSID(AP Name)Suleman
       
9. 
   10
   Enter the following command. This one will use the example information above, but you should plug in your own. Command: "airodump-ng -w wep -c 1 -- bssid 00:17:3F:76:36:6E wlan0" (without quotes).
10. 
    11
    Allow setup to start.
11. 
    12
    Open a new terminal window. Type the following command, substituting the values for your own BSSID, Channel and ESSID. Command: "aireplay-ng -1 0 –a 00:17:3f:76:36:6E wlan0" (without quotes).
12. 
    13
    Open another new terminal window. Type the following command: "aireplay-ng -3 –b 00:17:3f:76:36:6e wlan0" (without quotes).
13. 
    14
    Allow setup to start.
14. 
    15
    Go back to the first terminal window.
15. 
    16
    Allow the data in this window to reach to 30000 or above. It will take 15 to 60 minutes (or more) depending on wireless signal, hardware and load on access point.
16. 
    17
    Go to the third terminal window and press Ctrl + c.
17. 
    18
    Pull up the directories. Type the following command: "dir" (without quotes). This will show the directories saved on it during decrypting.
18. 
    19
    Use a cap file. For the example, it would be the following: "aircrack-ng web-02.cap" (without quotes). The setup shown below will start.
19. 
    20
    Break the WEP encrypted key. After this setup completes, you'll be able to break the key. In this example, it was {ADA2D18D2E}.

sumber :-

Update Samsung Galaxy Wonder I8150 to Android Jelly Bean

I’ve always wanted to update my Samsung Galaxy Wonder to Android Jelly Bean; lately my cellphone became quite slow (especially after the latest upgrades to Android 2.3 from Samsung) and I always wanted to install Chrome and Google Keep that both require Android 4. Samsung does not provide any official release of Android 4, so I decided to go for a custom ROM. In particular, I’m using Android Jelly Bean, 4.2.2, CyanogenMod 10.1 ALPHA (Build 7).

I had quite a hard time to understand how to install it; basically because I had never installed a custom ROM. Moreover, the instructions to do that can be found on the web but I never found a complete tutorial that shows the procedure from the very start: they all assume that you have already done previous steps.

Then, I decided to write a complete tutorial (this is based on Windows). This assumes you have an external sdcard on the phone.

The update will wipe out all your data, so make sure you backup them first. Proceed at your own risk. You will also lose Samsung warranty.

PLEASE, if you have problems with this custom ROM, DO NOT post comments to this blog post: use the official discussion forum thread.

Make sure you read the whole tutorial first, before proceeding.

Disclaimer: All the tools, mods or ROMs mentioned below belong to their respective owners/developers. I am not to be held responsible if you damage or brick your device.

USB Drivers

Make sure you can connect your Android phone with the computer. If not, install the USB drivers for Samsung Galaxy W properly. The easiest way is to install Samsung Kies.

Install ClockworkMod recovery using Odin

Download Odin zip file: Mediafire (this is the original page with this information)

Extract the odin Multi_Downloader_v4.43.exe file and run it.

Download recovery-clockwork-6.0.3.4-ancora.tar.md5 and Ancora.ops (this is the original page with this information).

In Odin

• enable “One Package” in options
• Select the Ancora.ops file,
• load the md5 file with the “One Package” button

Now you need to put your phone it into download mode, in order to upload the clockworkmod recovery file:

• turn off phone,
• hold Volume Down + Home + Power Button for a while till the phone turns on.
• the phone will turn on and show some screen,
• plug in usb cable
• press Volume Up

At this point Odin should detect the connected phone

In Odin press the “Start” button, and the downloading should start (see the phone):

Wait for the download to finish (see Odin)

Now you can unplug and turn-off the phone.

Create a backup of the current image

Turn on the phone in the Recovery Mode: hold Volume Up + Home + Power Button for a while till the phone turns on (Note: this time it is “Volume Up”, not “Volume Down”). Release power button as soon as samsung logo appears and hold your volume up button + home button until clockworkmod recovery appears on the screen

To use the menus:

• Volume buttons to move in the menu
• Home button to select a menu
• Power button to go back

Select “backup and restore” and then “backup to external sdcard”:

and wait for the backup to complete

You can now reboot the phone from the main screen. The phone will reboot as usual.

You may want to store a copy of the backup in your computer hard disk; just connect the phone with USB, and navigate to the directory where the backup was saved on the phone sdcard:

Perform the update

Download CyanogenMod 10.1 ALPHA (Build 7) and Google Apps

(this is the original source with the links)

Put these files in the root folder of your external SD card (you can turn on the phone as usual and connect it via USB for that, or copy these files from the computer using an external card reader).

When the copy finished, disconnect the phone and turn it off.

Switch ON the phone in the Recovery Mode: pressing and holding Volume Up + Home + Power buttons together.

Now wipe data and cache selecting the following commands (and wait for them to complete)

• Select “wipe data/factory reset”
• Select “wipe cache partition”
• Select “advanced” and then select “wipe dalvik cache”

Now go back to the main menu (Recall: use the power button to go back)

Select “install zip from sdcard” and choose the zip file containing the OS (in this case it is cm-10.1-20130611-EXPERIMENTAL-ancora-alpha7.zip) from the root of the SD card (where you previously copied it).

Now do the same for the google apps zip file: select “install zip from sdcard” and choose the zip file containing the OS (in this case it is gapps-jb-20130301-signed.zip) from the root of the SD card.

Reboot into the new system

Now you’re ready to reboot into the new system from the main menu!

NOTE: Your Phone will boot now and it might take about 5 minutes to boot on your first time. So, please wait.

If everything went fine, you should see the new logo

Then you should see all the menu screens for configuring the phone!

Note: as for me, this procedure started with an error message saying that the vocal synthesis engine crashed, but I simply ignored the message and went on.

After you inserted your Google account, the phone should be ready; at this point, if you selected an Internet connection, all the applications you had previously installed from Google Play should be installed automatically… it took about an hour in my case.

link

How to install Android KitKat on Galaxy S2 with CM 11

I shared the good news this morning that CyanogenMod have added the Galaxy S2 to their list of supported devices for the CM 11 ROM based on Android 4.4 KitKat. I've been running CM 11 for a couple of months now and have been very impressed. Now, you can get the same KitKat experience on the aging but still wonderful international model Galaxy S2 I9100. Here's how to do it.

The Galaxy S2 gets new life with CM 11 courtesy of CyanogenMod. / © Samsung, Cyanogen Inc, AndroidPIT

Warning

The installation of custom ROMs is risky, so if you do not follow the procedure properly, you can end up with an unusable phone. Back up all your data first, charge your battery and proceed with caution. Neither AndroidPIT nor myself will be held responsible for any damage done to your phone as a result of this process.

Prerequisites

I'll assume that your Galaxy S2 (I9100) is rooted and you have already made a Nandroid backup of your system. If you're not rooted and are unsure how to root your Galaxy S2, check this S2 root tutorial. You should also backup your app data too as this process will wipe your device.

Downloads

Download the latest CM 11 Nightly for the Galaxy S2 I9100. As always, there's nothing preventing you from flashing a newer version, once it is available.

Also download the Google applications package for KitKat: gapps-kk

Install Android 4.4 on the Galaxy S2 KitKat with CM 11

Since your S2 is rooted, we will use the good old custom recovery method. As a reminder, here is the procedure:

1. Download both zip files given above on your Galaxy S2.

2. Place both files in the root directory of your S2.

3. Turn off the Galaxy S2 and restart in Recovery Mode (Home + Power + Volume Up until the logo appears or the third vibration and release).

4. Perform a factory reset by selecting and confirming the option "Wipe Data/Factory Reset" then "Wipe Cache". Some users prefer to ''Format System'' / ''Wipe Dalvik Cache'' at this point too.

5. Then select "install zip from sd card" and locate the CM 11 zip you downloaded before.

6. Click "Yes" to confirm.

7. Next, flash the gapps zip file.

8. Return to the main Recovery Menu and select "Reboot System Now".

The first reboot on CM 11 may take a few minutes. Let us know how you like it!

Via: XDA Developers Source: CyanogenMod

sumber :-

Nuffnang Ads Panduan Galaxy Note II (N7100)

Page Panduan Galaxy Note II (GT-N7100) ini merupakan page khusus yang diwujudkan bertujuan memaparkan segala aspek yang berkaitan dengan model smartphone GT-N7100 dari aspek root, firmware update, tips dan trick dan sebagainya yang berkaitan secara setempat.

Info

• Spesifikasi Dan Drop Test
• Galaxy Note II (Pink Version)
• Hands-on (Video)

Panduan Upgrade Firmware Galaxy Note II (GT-N7100)

• Disember 2013 – Android Jellybean 4.3 XXUEML3 (Malaysia) – Latest!
• June 2013 – Android Jellybean 4.1.2 XXDMF2 (Malaysia ) – Outdated!
• Android Jellybean 4.1.2 XXDMC3 (Malaysia) – Outdated!
• Android Jellybean 4.1.2 XXDMB4 (Malaysia) - Outdated!
• Android Jellybean 4.1.2 XXDLL7 (Malaysia) - Outdated!

Panduan Rooting Galaxy Note II (GT-N7100)

• Cara – Cara Root Galaxy Note II (N7100)

Tips & Tricks

• Cara Memadam Bloatware Dari Android Smartphone
• Tips Mengurangkan Lag Di Peranti Android
• Cara Atasi Aplikasi Force Close Di Android
• Cara Dapatkan WiFi Password Di Android Smartphone
• Tips Jimatkan Bateri Android Smartphone
• Kenal pasti Punca & Cara Atasi Bateri Android Cepat Habis
• Cara Atasi Kies Not Support Software Upgrade / Tukar CSC

How To

• Cara Melakukan Nandroid Backup
• Cara Melakukan Backup EFS File
• Cara Mematikan Bunyi Kamera (Shutter Sound) Samsung Android Smartphone
• Cara Repair Micro SD Card (Damaged SD Card)
• Cara – Cara Menggunakan PC Odin Untuk Flash / Upgrade / Downgrade / Root
• Reset Binary Counter & Exclamation Mark (Samsung)
• Sembunyikan Folder dan Imej dari Galeri (Android)

NOTA! : Page ini akan di update dari semasa ke semasa.

sumber : -

Galaxy S2 I9100 Receives Official Android 4.1.2 VJMS4 Jelly Bean OTA Update [How to Install Manually]

Galaxy S2 I9100 Receives Official Android 4.1.2 VJMS4 Jelly Bean OTA Update

Galaxy S2 GT-I9100 recently received its latest Jelly Bean Over-The-Air (OTA) update from Samsung via Android 4.1.2 VJMS4 official firmware. The firmware is currently available for download as OTA update as well as through Samsung KIES in select countries including Brazil.
However, those who missed the twin opportunities and those residing outside the supported countries can still download and install the same manually (provided the device is unlocked), using our step-by-step guide. NOTE: The installation of this OTA update does not require ClockworkMod recovery (CWM) or a rooted Galaxy S2 phone, as it can be installed manually via ODIN flash tool.
Android 4.1.2 VJMS4 Jelly Bean Official Firmware
PDA: I9100VJMS4
CSC: I9100ZTAMS4
Version: 4.1.2
Date: May, 2013  

 Key Points to Note

• Android 4.1.2 VJMS4 official firmware and the instructions provided in this guide are applicable to the Galaxy S2 GT-I9100 model only. Do not attempt installing this firmware on any other device, as it may inadvertently damage or brick the device. Verify your device's model number by navigating to Settings > About Phone.
• Back up your important data and settings on the phone including contacts, messages, photos, videos, MMS and APN settings to an external SD card to prevent data loss while performing any data wipe task during or after firmware installation.
• Ensure the phone has at least 80% battery charge to prevent unexpected device shutdown (due to battery drain) during or after firmware installation.
• Verify that correct USB drivers for the phone are installed on computer (download Samsung Galaxy S2 GT-I9100 USB drivers)
• Ensure USB debugging mode is enabled on the phone to facilitate data transfer between phone and computer via USB cable. To enable USB debugging mode, navigating to Settings > Developer Options (if device is running Android 4.0 or later) or Settings > Applications > Development (if device is running Android 2.3 or earlier). If the phone is running Android 4.2, perform the following steps:
• Go to Settings > About Phone
• Scroll to the bottom of the screen and select Build Number
• Tap the phone's Build Number seven times to unlock or reveal the hidden Developer Options under Settings. Then select the checkbox to enable USB debugging mode under Settings > Developer Options.
• Ensure the device is factory unlocked (not locked to a specific carrier) and its bootloader is unlocked.
• The installation of the firmware requires ODIN flash tool, which is designed to work on Windows OS only. Linux and Mac OS users should use CrossOver Utility to run ODIN on their computer.
• Instructions provided in this guide are meant for reference purpose only. IBTimes UK will not be held liable if the device is damaged or bricked during or after firmware installation. Users are advised to proceed at their own risk.

Downloads

• Android 4.1.2 VJMS4 Jelly Bean firmware for Galaxy S2 I9100
• Odin v3.07

How to Update Galaxy S2 GT-I9100 on Official Android 4.1.2 VJMS4 Jelly Bean Firmware

Galaxy S2 I9100 Receives Official Android 4.1.2 VJMS4 Jelly Bean OTA Update

Step 1: Extract the firmware zip file to the desktop to get a .tar.md5 file and some other files (optional).
Step 2: Extract Odin zip file to obtain Odin3 v3.07.exe along with few other files.
Step 3: Power off the phone and wait for vibration (about 5-6 seconds) to confirm complete device shutdown. Now boot the phone into Download Mode by pressing and holding Volume Down, Home and Power button together until a construction Android robot icon with a triangle appears on screen. Then hit Volume Up button to enter Download Mode.
Step 4: Launch Odin3 v3.07.exe that you obtained in Step 2 as an Administrator, as Admin privileges are required to complete the firmware installation process smoothly.
Step 5: Connect your phone to computer via USB cable. When the device connects successfully, the message saying "Added!" appears in ODIN and the ID: COM box will turn yellow with the corresponding COM port number. If the message fails to appear, try reinstalling the phone's USB drivers or changing the port on the computer.
Step 6: Choose the following files from I9100VJMS4 folder that you obtained in Step 1 in Odin using respective checkboxes:

• Select the PDA checkbox, and click the .tar.md5 file
• Tap the Phone checkbox, and select the file named 'modem' (ignore if such file is not found)
• Choose the CSC checkbox, and click the file named 'CSC' (ignore if there is no such file)
• Click the PIT checkbox, and choose the '.pit' file (ignore if the file is missing)

Step 7: In Odin, enable Auto Reboot and F. Reset Time options by selecting the checkboxes. But the Re-Partition checkbox must be selected only if a .pit file was chosen in the previous step in ODIN.
Step 8: To prevent ROM related errors, verify Step 6 and Step 7 are done correctly. Then hit the START button to begin flashing the firmware.
Step 9: Once the firmware installation is complete, the phone will reboot automatically and soon a PASS message with green background appears in the left-most box at the very top of Odin. Now it is safe to disconnect the USB cable to remove the device from computer.
The Galaxy S2 GT-I9100 is now running on the latest Android 4.1.2 VJMS4 Jelly Bean OTA firmware. Go to Settings > About Phone to verify the firmware installed.
Troubleshooting:
If the phone is stuck at boot animation or Samsung logo after Step 9, then go to recovery mode (press and hold the Volume Up, Home and Power buttons together) and perform Wipe data/Factory Reset as well as Wipe Cache Partition before choosing reboot system now option. Use Volume keys to navigate between options and Power key to select an option in recovery. Please note that performing data wipe task will only erase your phone's internal memory and not the data on SD card.
[Source: Droid Firmwares]

How to Update HTC HD2 with Android 4.1 Jelly Bean Firmware

HTC HD2 is one of those phones, feed anything and it will happily run the OS. This time, Android 4.1 Jelly Bean is now available for the HTC HD2. This is obviously not an official ROM by any means. It is developed by a third-party developer. Jelly Bean for HD2 is in an early stage with lots of features and options not working.
In this tutorial, we will tell you how to install Android 4.1 Jelly Bean on HTC HD2 with complete step-by-step guide. First, you will need to take care of some per-requisites like backing up your phone etc.




Disclaimer: All the tools, mods or ROMs mentioned below belong to their respective owners/developers. We (TeamAndroid.com) or the developers are not to be held responsible if you damage or brick your device. We don’t have you on gun point to try out this tutorial

Working:

• Mobile Data 3G/2G
• Calls
• WiFi
• Bluetooth
• SMS
• Sound check download page for fix
• Video Playback
• USB Mass Storage

Not Working:

• Camera
• Browser works but display is messed up.
• Error when Installing some Apps
• Google Now crashes.

Make sure you have installed all your USB drivers for the HTC HD2 to connect it with the computer. Apart from just the USB drivers, there are a few more things that you need to take care of. The following options are mainly for if your HTC HD2 is on Android.

1. You need to enable USB debugging mode. This helps to connect your Android phone with the PC. See here: How to Enable USB Debugging.

2. Your phone battery should be 80-85% charged. If your phone goes off suddenly because of battery, during flashing ROMs or installing mods and updates — your phone might go dead permanently. See here: How to Check Battery Percentage.

3. Backup all your important data that you might need as soon as your flash a new ROM, or make a backup for just in case, you never know when anything might go wrong. See below on how to backup data:

• Backup your SMS messages. How? –> How to Backup/Restore SMS Messages.
• Backup Contacts, Gmail and Google Data. How? –> Sync with Google Sync.
• Backup Call History. How? –> How to Backup Call History.
• Backup WhatsApp Messages. How? –> How to Backup/Restore WhatsApp Messages.
• Backup APN Settings: GPRS, 3G, MMS Settings.

4. Your phone should be factory unlocked. Additional instructions for locked Android devices will be added in the tutorial for unlocking devices.
Now, let’s proceed with the tutorial on the next page and update HTC HD2 to Android 4.1 Jelly Bean custom ROM.


link

Galaxy S2 GT-I9100 Receives Android 4.1.2 XWLSU Jelly Bean OTA Update [How to Install and Root]

Another official Over-The-Air (OTA) update, Android 4.1.2 Jelly Bean with base firmware XWLSU, has been released for Samsung's second generation Galaxy S series smartphone bearing model number GT-I9100. The new official build is for Orange subscribers in various countries such as Romania, Austria, France, Poland and Spain.

Android 4.1.2 XWLSU Jelly Bean update is available for Galaxy S2.

 Firmware details
PDA: I9100XWLSU
Version: Android 4.1.2

Regions: Austria, Belgium, France, Germany, Hungary, Italy, Spain and United Kingdom
This is a carrier branded firmware and like other branded official firmware the latest build is not available over Samsung Kies. Users can connect the device to Wi-Fi and find the OTA update by navigating to Settings>> About device>> Software update.
   
Those who fail to find the OTA update for being region-specific may follow our step-by-step guide to install Android 4.1.2 XWLSU Jelly Bean manually using Odin flashing tool.

IBTimes UK reminds its readers that it will not be held liable for any damage to the device. Users are also advised to verify that their handsets meet the following requirements.

Pre-requisites

1) Install USB Driver for Samsung Galaxy S2 to connect the Android device with the computer.
2) Enable USB Debugging Mode on the phone to connect it with the computer and use Android SDK with it. [Press Menu>> Settings>> Applications. From there navigate and click on Development option and ensure the USB Debugging Mode is turned on.]
3) As the tutorial might wipe out all data of the phone, create a backup. If the device is having any custom recoveries such as CWM/TWRP already installed then backup data using the recovery.    
4) The battery of Galaxy S2 should have above 80% charge.
5) The device should be factory unlocked and not locked to a particular carrier.
6) The phone will lose custom ROM with the installation of official firmware. Additionally, it will lose custom recovery such as ClockworkMod/TWRP which will be replaced by stock recovery.
7) The device will no longer belong to a rooted version with the installation of official firmware.
8) The Android 4.1.2 XWLSU Jelly Bean works only on Samsung Galaxy S2 GT-I9100. As flashing this on any other variant might brick the device, verify the model number of Galaxy device by navigating to Settings>> About Phone>> Model number.

Steps to install Android 4.1.2 XWLSU Jelly Bean on Samsung Galaxy S2 GT-I9100 

Step-1: Download Android 4.1.2 XWLSU Jelly Bean official update for Samsung Galaxy S2 to the computer
Firmware download links: Android 4.1.2 XWLSU Jelly Bean (Poland)/ Android 4.1.2 XWLSU Jelly Bean (Spain) / Android 4.1.2 XWLSU Jelly Bean (France) / Android 4.1.2 XWLSU Jelly Bean (Austria) / Android 4.1.2 XWLSU Jelly Bean (Romania)  

Step-2: Extract the downloaded zip file to get a file with .tar.md5 extension along with few other files

Step-3: Download Odin v3.07 which will help to install the Jelly Bean firmware on the phone. Extract the Odin zip file to get Odin3 v3.07.exe file with some other files

Step-4: Switch off the Galaxy S2. Now place the phone in Download Mode by pressing and holding the Volume Down and Home buttons together while pressing the Power button. A warning screen will appear, now press the Volume Up button to continue to enter Download Mode   

Step-5: Run Odin3 v3.07.exe as an Administrator on the computer

Step-6: Connect the Galaxy S2 to the computer using USB cable while it is in the Download Mode. Wait until Odin detects the device. When the phone is connected, a message saying Added will appear under Odin's message box. Also, the successful connection will be indicated by the ID: COM box in Odin turning yellow with the COM port number

Note: If the Added message does not appear, then try the USB port at the back of the computer. In case that too does not work, then re-install USB driver.  

Step-7:  Select these files extracted from I9100XWLSU folder to install on the phone
a) Click the PDA button and select the .tar.md5 file
b) Click the Phone button and select file with Modem in its name
c) Click the CSC button and select file with CSC in its name
d) Click the PIT file and select the .pit file   

Step-8: Ensure the Auto Reboot and F.Reset Time checkboxes are selected in Odin window. But uncheck the Re-Partition option, select it only when a .pit file is being used

Step-9: Double check everything and click the Start button in Odin. The installation process should begin now and would take few minutes to complete

Step-10: Upon the completion of the installation process, the phone will restart automatically. And soon a PASS message with green background will appear in the extreme left box at the very top of Odin indicating successful installation. When the home screen appears on the phone, unplug the USB cable from the device to disconnect it from the computer

Samsung Galaxy S2 should be now updated with Android 4.1.2 XWLSU Jelly Bean official firmware. Navigate to Settings>> About Phone to verify the new software version running on the device.      
Fix bootloop issue 

If the Galaxy S2 gets stuck at booting animation (after step-10), then put the phone into recovery mode by pressing and holding Volume Up, Home and Power buttons together. Now perform data wiping task by selecting Wipe data/factory reset, and then select Wipe Cache Partition. Once the action is completed, return to the main recovery menu and reboot the phone by selecting reboot system now. In recovery mode, use Volume keys to navigate between options and the Power button to select the desired option. Performing data wiping task will erase the internal memory data of the device.       

Those who have already installed Android 4.1.2 XWLSU Jelly Bean on their devices, may follow our step-by-step guide to root the same.

Steps to root Samsung Galaxy S2 GT-I9100 on Android 4.1.2 XWLSU Jelly Bean 

Step-1: Download Rooted Speed Kernel for Samsung Galaxy S2 to the computer
File name: speedmod-kernel-s2-jb-k5-3-Odin.tar    

Step-2: Download Odin 3.07 and extract the downloaded zip to get Odin3 v3.07.exe along with few other files

Step-3: Switch off the Galaxy S2 and wait for about five to six seconds to confirm complete power off

Step-4: Boot the phone into Download Mode by pressing and holding Volume Down and Home buttons together while pressing the Power button. A warning screen will appear, then press the Volume Up button to enter Download Mode   

Step-5: Run Odin3 v3.07.exe as an Administrator

Step-6: Connect the Galaxy S2 to the computer while it is in the Download Mode

Step-7: In Odin, click the PDA button and select speedmod-kernel-s2-jb-k5-3-Odin.tar file

Step-8: Verify that the Auto Reboot and F.Reset Time checkboxes are selected in Odin window. But uncheck the Re-Partition option

Step-9: Finally, click on the Start button in Odin to begin the installation

Step-10: Once the installation process is completed, the phone will reboot and soon a PASS message with green background will appear in the extreme left box at the very top of Odin. When the home screen appears on the phone, disconnect the device from the computer

Samsung Galaxy S2 running on official Android 4.1.2 XWLSU Jelly Bean should now be rooted successfully. Users may now install any app that requires root permission.
Click here for tutorial to install Android 4.1.2 XWLSW Jelly Bean on Samsung Galaxy S2 I9100.

source