A few things before I upgrade from 3.1.3 to 4.0

[40ozBulldog]

Okay so im going to use this guide here http://modmyi.com/guides/?p=3260 to upgrade but before I do I want to know a few things.

Im running a iPhone 3G on 3.1.3 (7E18) Im on T-mobile and want to know if it will lock the phone again. Also, it took me forever to figure out MMS on the phone and I dont want to lose that will I? I have multiple apps that I dont want to lose so basically I want to know if upgrading changes anything on the phone or locks it.

Thanks for the help. Sorry for the noobish thread but just want to make sure and ive never done it before.

[dhamien]

The guide you linked to is for redsn0w. Redsn0w is simply a jailbreaking tool. It doesn't update or restore your phone.

If you're going from one firmware version to another, you will lose all apps and settings and will need to reinstall those after the restore. You will also need to reapply the unlock after a restore. Another thing about the unlock is that you can not restore to a version that has a baseband that isn't unlockable. Currently, the only firmware version that has a baseband that isn't unlockable is the 4.1 firmware. All other firmwares are jailbreakable and unlockable on a 3G phone (4.1 is jailbreakable too, but if you go to 4.1 with stock firmware you will lose the ability to unlock, possibly forever).

[40ozBulldog]

So it looks like ill be staying on 3.1.3 Thank you!

[eyeRobot]

It's quite possible to go to a snowbreeze cooked 4.1 firmware with your phone and then restore it's settings and apps through a backup in itunes.

1 hr max.

If you have jailbroken apps then that will take a little longer to add all those back in.