Restoring the original IMEI number (written on the box or behind the battery) to a phone that lost it due to a software error is generally legal. You are fixing, not cloning.

A: No. A factory reset only wipes user data (contacts, apps). It does not touch the NVRAM or modem partition. You need a flash tool.

Imagine this: You turn on your Nokia 8000 4G, eager to make a call, but you see "No Service," "Invalid IMEI," or "IMEI Null." Your phone has become a glorified MP3 player. This is where comes into play.