I’ll be explaining how to reset your Nokia phone i.e without flashing. Resetting a phone is almost similar to flashing a phone only that you won't be loosing files rather you'd loose every settings which includes security settings as well.
If you wish to flash your phone - See more at: https://forum.hovatek.com/thread-3464.html
The process shouldn't be interrupted due to insufficient charge on the battery or due to disconnection of the USB cord as it may result to a totally damaged phone. I shall not be held responsible for inability to follow procedures correctly.
* Phoenix Service Suite
* Nokia PC Suite
* Firmware files (best if it is the same version currently on the phone)
* A GOOD USB cable
* Phone to be reset (we are going to use asha 302 as example)
* 50% charged battery
* Install Nokia PC Suite
* Install phoenix
* DOwnload your phone's firmware files from Nokia Firmwares
* After successfully downloading all files required for your phone, goto C:\Program Files (x86)\Nokia\Phoenix\Products
* Create a folder inside the directory above and rename the folder to your phone's product type. E.G Nokia asha 302 should be renamed as RM-813
* Copy and paste all downloaded files into the newly created folder. use the picture below as reference
* Start Phoenix
* Power off the phone
* Connect your phone through USB Cable
* Click File > Open Product.
* Select your RM code from the window that appears. Click OK (see pic below)
NOte: for asha 302, we'd select RM-813
* Click on the Flashing tab > select Firmware Update. (see pic below)
* Check the option “Dead Phone USB Flashing”
* Click the small box beside product code and select your phone's firmware (see pic below)
* Click SW Reset and the phone reset process should start.
* The process might be halted and you would be asked to remove battery etc. simply follow all the processes as seen on your PC screen
* Your phone should automatically startup when the reset is complete.
* Once completed successfully, you can safely remove your USB from the phone