I guess, your phone has infected by a virus/Malware! you may have re download original firmware.
resetting doesn't make any sense when virus infected to boot loader or anyhow got root permission / administrator rights on your phone :-( .
Most of time, OS install via SD card (dload) will works for you ( solution is depends on the virus that infected you phone) otherwise you have to go for flash via flash tool.
Xda will help you to get more information
Hope this answer will help you to fix your device!