HELP! Can't upgrade to 4.2.1

[Capitan Totti]

Can't seem to upgrade my iPhone 3G to 4.2.1. I restore fine to 4.1, but once I try to restore 4.2.1, nothing... it only shows the restore mode telling me to connect to itunes. Why? I do get error 1015, I kick the phone out with TinyUmbrella, it works with 3.1.3 and 4.1... not with 4.2.1...

[iYeow]

You have the ipad baseband , that is why you cannot restore to stock 4.2.1.
You can restore to custom firmware of 4.2.1 but you have to use redsn0w to put you into dfu mode ( Geohot's DFU ) before running itunes and restoring to cfw of 4.2.1 or higher.

[i.Annie]

And TinyUmbrella isn't supposed to work on 4.2.1, that's why.

Be sure the custom fw doesn't include the iPad baseband or you'll error out again.

Just follow iYeow's steps.

[Capitan Totti]

YesI figured that on my own after a bit. I managed to upgrade it to 4.2.1. Now I am having issues with SAMPrefs... just can't figure out how to activate the phone!

[iYeow]

Run redsn0w 0.9.6RC8 to hactivate and jailbreak for you. Then go to cydia, install SAM repo and install the Sam tools.

[Capitan Totti]

If SAM gives me the De-Activate option in Utilities, even if the phone it says its Unactivated, what does this mean? I couldn't get into iTunes before, but now it seems to be working. I just wanna know if clicking De-Activate is indeed what I have to do to make SAM work or not. Thanks.