Really need help urgently!!

Hi, first post and its a bit of an urgent one.

I've just got home for lunch having left my phone at home and my little brother has tried to install os4 onto my phone for me whilst i was out as a surprise for when I collected it.

When I got in he had just freaked and left it sat on the itunes window that reads

'This phone is not registered as part of the developer program.'

Now I wasnt really panicked as i thought i would be able to restore to 3.0. However there are no options anywhere in sight. Any advice on how I can restore it back to its original settings?

Thank you.

Turn you phone off completely. Open iTunes on your Mac/PC.

Hold down the Home button AS YOU PLUG IN THE PHONE to your computer.

iTunes will say something like "iTunes has found an iPhone in recovery mode. Restore this iPhone to repair it".

Proceed with the repair. It will automatically download and install the latest, non-beta release of iPhone OS/iOS.

Take note this process WILL ERASE EVERYTHING on your phone.

Tell your brother to do a bit more research on the subject next time. Evidently he got his hands on a developer build of iOS4 and not the proper GM version.