How to Fix Sony Xperia S Problem While Connecting to PC
I think the Sony Xperia S is very good looking and easy to use smartphone, but there are also many bads on it in my experience. When I first time tried to connect my Sony Xperia S to PC (Windows 7 OS) via USB cable, my PC couldn't detect my Sony Xperia S even after having installed the PC Companion. Finally I found two methods to solve this problem.
Method 1: Clear MTP App
After clearing the data stored by MTP App on internal memory, suddenly Sony Xperia can connect to PC and works good. The steps are below:
(1) Disconnect the Sony Xperia S from the PC.
Unplug the USB cable from the computer or the smartphone.
(2) Clear data for the MTP App.
Goto Settings -> Applications -> Manage Applications
Click on All (1), click on MTP extension service (2) (the App's name might be different to yours, but must have a MTP word in its name)
Click on Clear data (3), and then reconnect Sony Xperia S to your computer. PC Companion will successfully detect your phone as expected. But you will to repeat this method (Clear the MTP data in the phone) when you try to connect your Sony Xperia S to your computer everytime.
Method 2: Software update
Goto Settings -> About phone -> Software update.
Update the Sofeware and System to the last version, and then this problem will be solved automatically.