Nokia Lumia 720 data:
GSM frequencies :850 900 1800 1900
Standard UMTS :850 900 1900 2100
Type :Touch
Dimensions (W x H x D) :127,90 x 67,50 x 9,00 mm
Weight :128,00 g
Main display :Color / IPS TFT
16M colors
480 x 800 px (4.30") 217 ppi
Talk time (max.) :2G: 1404 min. (23,4 h)
3G: 804 min. (13,4 h)
Stand-by (max.) :3G: 520 h. (21,7 days)
Standard battery :Li-Ion 2000 mAh
Internal memory :8 GB
RAM memory :512 MB
Memory cards : microSD, microSDHC, microSDXC (up to 64 GB)
Operating system :MS Windows Phone 8
Processor :Qualcomm MSM8227
Processor clock :1,00 GHz
How to hard reset:
Warning! All data will be lost!
1.Turn off your phone
2.Push power key and after phone vibrates once press volume down until you will see exclamation sign on the screen
3.Push the buttons in this order:volume up
volume down
power
volume down
4.Wait until format ends and the phone restarts
That's it
Here is video how to do: