Rooting sounds complex, but in some cases is extremely easy to undertake. It will let you customise your phone in a variety of ways and also let you install custom ROMs which can offer specific features or performance improvements to any Android smartphone.
Every Android phone is different, however, and there are different rooting methods for each manufacturer and sometimes for each phone made by the same company.
We will demonstrate how to root four popular Android phones and as you can see, the methods vary wildly. It is also advisable to only root your smartphone if you need the extra capabilities it offers.
Rooting can make a smartphone unstable and it is generally acknowledged that the more difficult the rooting process, the less likely it is to be successful.
If you follow the processes completely, however, you should have no problems, but take note of any error messages to ensure things are as trouble-free as possible.
Rooting an Android phone can open it up to a wealth of possibilities and you can do so in a variety of ways.
Rooting method 1 for Samsung Galaxy S II
Rooting method 2 for HTC Sensation XE
Rooting method 3 for Motorola Razr
Rooting method 4 for Sony Ericsson Xperia Arc S
Source : Android Tips, Tricks, Apps and Hacks