Samsung Galaxy S2 stops during boot My S2 stops at the Samsung logo screen during boot. When I restart it, the same thing happens. My phone is using Android 4.0.4 (ICS), and it is not rooted. Please help me with this. Thanks in advance.
Sometimes android goes into Fubar mode and the only way to get past it is to make a hard reset. This unfortunately deletes any data stored on the device but anything stored on the memory card will remain. Luckily there is a hardware hard reset mode.

A hard reset can be accomplished by doing the following things:


Turn the power off. If your Samsung Galaxy S II is frozen, pull the battery out and reinsert it
Hold the Volume Down button
Press and release the Power button
You are now presented with a menu that allows for Fastbook, Recovery, Clear Storage, and Simlock
Select Clear Storage by pressing the Volume Down button
Press and release the Power button
Now simply confirm your decision: Volume Up for YES and Volume Down for NO


Some versions of samsung galaxy s2 require that you need to hold down volume down AND volume up to get into the menu.

Youtube video showing how it's done