There two types of software running the phone and users requirement; Operating system and applications. Both can be malfunction and showing ghost behavior due to virus infection via internet or due to frequent installation and un installation of software. Sometimes software and applications up-gradation also triggers issues. These software faults can be due to hardware faults. But these faults are needed to be addressed carefully as these can damage your valuable data including pictures, contacts and so on.
So as soon as you observe your Nokia Lumia 820 behaving un-predict consult our expert and skilled technicians. You can visit us at our service centre, have a live chat with us, call us at 04 4211494 or email us at firstname.lastname@example.org. You can also avail our free PICK & DROP service