What you are trying to do is a soft reset.Its not working may be because you havent registered your phone yet.
You can try Hard resetting your phone. This will erase all data on your phone excluding what is there on your SD card
Follow the following steps :-
1. Turn off your phone.
2. Press the home key and the red power button for 30 seconds untill you see a triangle with an exclamation mark at center.eep holding it even though the G1 logo shows up.
3. Now you have the following options with you:-
(i) ALT + L --> Toggle log text display b/w exclamation and menu options.\
(ii) ALT + S --> Apply SD card update
(iii) ALT + W --> Wipe data and factory reset
(iv) HOME + BAC --> Reboot of your mobile
you can then select any of the following options
[FONT=Lora, georgia, serif]Thank you.Hope this helps.