Best way to unjailbreak/restore iphone 3G successfully?

[speedious]

What is the best way to unjailbreak or restore iphone 3G successfully?

Please be detailed...on how about doing it. Thanks in advance.

[461am]

Open itunes and hit the restore button.

[speedious]

Will restoring it thru itunes....ask me to activate my iphone 3G again?

[461am]

As long as you're not doing any of those simhacks and are in fact on an iphone contract, it will auto-activate.

[speedious]

If on iphone contract...why will i post my question here....

I will straight away contact AT&T.

What are the choices for unlock sim adapters?
What about non-active AT&T sims?

[littlemadamb]

I just bought a 2nd hand iphone 3gs (told was standard and NOT jailbroken) and at first it would connect and sync to my computer but i couldnt transfer all my apps. I had to buy new ones and transfer my music manually.
Went to update it last night and my husbands iphone 3gs updated fine but when he plugged mine in it asked to be restored to factory settings as there was a problem. When we tried to do that it got to the verifying part of the restore then came up with error 1015 and can go no further.
Cant use the phone at all as its got a symbol asking to be plugged into itunes.
itunes etc is all up to date...HELP cos i havent a clue what to do now (