Trying to upgrade to 4.0.1 (3194) error!

[JazzyStahh]

I am trying to upgrade my firmware to 4.0.1 on my iPhone 3g 3.1.2 but everytime I hold down shift and click restore select the ipsw file I get a error, check the picture below. The phone just has a usb cable then itunes symbol on top. And it just restarts! I don't get what I am doing wrong! Any help will be appreciated!

[Simon]

You need SHSH for 4.0.1 to restore to 4.0.1

[JazzyStahh]

Sorry I am pretty new to all this, how do I get the SHSH?

[Simon]

Download tiny umbrella and press save SHSH with your phone connected.

[JazzyStahh]

I downloaded tiny umbrella and connected my phone but the save SHSH button is greyed out (disabled)

[Simon]

Do you have the latest version from here: http://thefirmwareumbrella.blogspot.com/

[JazzyStahh]

Yes I do and again let me just say that i am trying to upgrade to 4.0.1 from 3.1.2 as I have seen some other sites claiming they need SHSH only for downgrading?

[Simon]

You need SHSH for any 4.x firmware that is not the most current. Why are you trying to go to 4.0.2 though? Why not 4.2.1? Do you require unlock?

[JazzyStahh]

Yes I do, I live in the UK and the phone I think originally is locked to T-Mobile and I need to use it on Three Hutchisons!

[Simon]

You can install a custom 4.2.1 to preserve your baseband and unlock after. It will run better than 4.0.2. If you dont have access to a Mac just pm me for a custom 4.2.1

[JazzyStahh]

So will I be able to unlock it straight after I put on custom 4.2.1?

[Simon]

You will just need to download and install ultrasn0w from cydia after.

[JazzyStahh]

That's great! Could you please send me the custom 4.2.1 then?