It is quite common to see the degradation of performance on your mobile device after a certain period of time. It is most probably due to the heavy storage of media file, SMS or application stored in the device. Running out of memory due to background application may also cause the lag in performance and normally end up with a force close for the running application. We believe most of you may experience this situation on any mobile devices.
If the frequency of force close is high, then it act as an alarm for you to restore your device to previous condition where no force close is encountered. The simplest way to restore your device is to perform factory reset. Factory reset, by meant, to restore your device to the factory condition whereby all of your data will be wiped. Before you perform factory reset, we recommend to backup all data including contact, SMS history, Whatsapp chat history, applications etc to external storage.
How to Factory Reset Sony Xperia Z
1. Go to Settings. You may access to the Settings through the pull-down menu. Settings button is located at the top right corner.
2. Scroll down to locate Back up and reset tab.
3. Optional: You can backup all data to Google Servers under Back up and reset.
4. Press on Factory data reset to perform factory reset. Be warned! All data will be wiped after Step 4. Please make a back up.