How to restore an unlocked Iphone 3GS to factory settings?

I've got a question that I'm hoping you can help out on - I've trawled through forums/websites trying to find out how to fix my iphone.

I bought it off a friend in London, before moving to Canada.

I had it unlocked in London, and it took the Iphone 3GS back to 4.1 setup and the guy said I couldn't download any new apps otherwise it would screw it up (and lock it again). My friend recently jailbroke his iphone, then unlocked his himself and it's working fine. Since I couldn't use/download new app's on my iphone, I wanted to do the same. I tried using Absinthe to jailbreak my phone, but it wouldn't work, so I tried updating the software to IOS 6.0 (as I thought I'd then be able to use a programme to jailbreak it after I updated the software). Unfortunately, now I can't use any simcard in the phone to get into it (rendering it useless).

I've tried downloading an old 4.1, and attempting to restore my iPhone through iTunes with it, but this isn't working - brings up 'Iphone can't be restored. An unknown error occurred (20)'

Is there anything else I can do to fix the phone? I'm struggling to find anything else I can do.

Would appreciate any assistance.

With the help of a phone technician.

Mate the same thing happen to me on my iPhone 3GS but i finally got it to restore with iPhone5Break
this got my iPhone to work perfect.

Check out the link below
http://www.iphonehacks.com/2008/10/virginizeiphone.html
http://modmyi.com/forums/3g-s-downgrading/806566-how-restore-3gs-unlocked-jbd-factory-setting.html

IPhone can be unlock to any network such AT&T, Vodafone, O2, Rogers etc. The phone has to be unlocked, the SIM has to be cut into micro SIM and then you can pop it in the iPhone. There are many website which helps and guides you how to unlocked iPhone.

  • Will i lose my iphone contacts if i restore to factory settings? I have to restore to factory settings because of a really annoying problem related to downloading apps, will i lose my contacts if i restore to factory settings?
  • My iphone wants to restore to factory settings? Question is should i do it? it states it will erase all data and update so i'm not sure if i want to risk it incase it worsens the situation. i've updated itunes and tried again with no luck. Its annoying as i can't sync any cds onto it and it can't update… Is it worth the risk? Or should i just leave it and keep it as it is as i have no other problems with the phone.
  • My iphone 3gs won't restore to factory settings? I bought an iphone 3gs for $50 from my friend, it worked fine except i had to restore it. It automatically updated the IOS but when it finishes restoring it gives me a message that says something like: "itunes could not restore your device due to an unknown error(-0)." any idea on how i can fix it? Or does this mean my iphone is obsolete and will no longer work?
  • IPhone Spyware: Restored from backup. To late to restore to factory settings? Believe an Ex jailbroke and put spyware on my iPhone. Connected to my computer and iTunes but restore from a backup not to factory defaults. Concern is that if I do so now, is my computer and the restore already corrupted? Does iCloud make a difference?