The Step by Step guide :
- Connect phone to PC with USB cable. Remember to choose PC suite mode.
- Click Read Info. If it shows phone not found then click again on Read Info and this time when init connection appears, quickly remove the cable and insert it back. Phone details will be displayed.
- Select Test mode in the bottom right side and click the right arrow button (>). If nothing happens for 10-12 seconds then click Abort. Again click >; and after 2-3 seconds quickly remove USB cable and re-insert. After a gap of probably 3-4 seconds the phone should go dark, but it won't switch off actually, if you tilt the screen a bit and see it in light reflection, you'll see written test mode, NOKIA. You are now in Test Mode.
- Select Full Factory and then click Reset. When init connection appears remove the cable and re-insert. The phone will reboot and the defaults will be reset.