today t'm showing you how to resolve some miner problems of your phone such as slowing,stucking by reset your phone to factory defaults.Please mind that ,you must backup your dates,[contacts,images,and messages etc ,because factory reset will erase them all]

This is for your Samsung S2,I'll give you instructions for every famous models later.click onHow to Factory reset My Samsung S2 

This is a short video clip showing you how to do it.http://adf.ly/1WS1vD.