My carrier is completely lost after updating iphone 3g to a 4.2 version

[roxywww.me]

Hi, im new here, so i really will apreciate ur help. This morning i was trying to update my iphone 3g to a 4.2 version..so when it finished my carrier was just gone. I even dont have Carrier on General Settings. I dont have any problem with the internet, i can check my email account with no problem, but i dont have signal, and says Invalid Sim card sometimes. My carrier was T-mobile. Ive tried like everything but nothing works PLEASE SOMEBODY HELP ME!!!! Txhanks

ps> i dont have cydia either

[Pugsly]

Seems like you were trying to jailbreak the iphone, werent you? If that is the case then you will have to jailbreak it again. Make sure that activate was not ticked and try reinstalling the vanilla firmware and see how it goes. There are many jailbreak topics made on this forum that you can search to sucessfully restore your iphone.