In touch screen mobiles it can be software problem also if touch is not working well.To solve these problems try the following steps.
Charge mobile phone battery, Make backup of your impotent contacts data and media files if possible and in most cases take out SIM and SD card.
After reset of Nokia Lumia 820 you will lose all the data and it will be impossible to get it back.so online backup is always important. Try to save all your data, backup on external device or hard drive.
So lets start the Nokia Lumia 820 Restore Factory, Nokia Lumia 820 Hard Reset.
Turn Off the mobile phone for few mints.
Make it Power On
On the Start screen,
Tap Settings > about phone.
Tap reset your phone, and then tap yes.
The factory setting for the lock code is 12345
It will remove all the data ,contacts and apps that you installed
Sign up here with your email
Restore Hard reset will set your phone in origional factorry settings. It will remove all the data and apps that you installed. Your contacts will be removed and you have to add them again.
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