ClockworkMod (CWM) Recovery Mode allows you to install custom firmware via zip format in SD card. Besides, CWM also provides backup and restore functions in Nandroid. And other advanced functions too. ClockworkMod Recovery is a must install component because lot of the custom firmware are developed to be flashed via CWM. How to install ClockworkMod Recovery on Samsung Galaxy S II? Personally, I installed CWM through CF-Root. Besides getting CWM installed, I also have Samsung Galaxy S2 rooted. Isn’t that great?
Note – You need a CF-Root that matches your Samsung Galaxy S2 kernel version. Then use Odin3 to install it.