Hello,

I wouldnt consider myself a novice as being jailbreaking/unlocking myself since first iPhone 2G however, it just seems so much more complicated now a days. Because of that I've not gone past iOS4.0.1 on my iPhone 3G but there are quite a few apps now that i've wanted that require at least iOS4.1 so would like help here from you knowledgable folks if that is ok. Here's a bit about what i got:

Phone: iPhone 3G
Version: 4.0.1 (8A306)
Modem Firmware: 05.13.04
Unlocked: Yes (Will defo need whatever I update to, to 'hacktivate' it somehow too as handset from Canada, I'm in UK)
Jailbroken: Yes (Can't remember how)
Computer OS: Windows

So I would like to go the latest firmware possible on my iPhone 3G (untethered if possible). There seems to be soo much information and software out there I havent got a clue what or where to go.

Help me please... Thank you in advance

Originally Posted by GSP

I wouldnt consider myself a novice as being jailbreaking/unlocking myself since first iPhone 2G however, it just seems so much more complicated now a days. Because of that I've not gone past iOS4.0.1 on my iPhone 3G but there are quite a few apps now that i've wanted that require at least iOS4.1 so would like help here from you knowledgable folks if that is ok. Here's a bit about what i got:

Phone: iPhone 3G
Version: 4.0.1 (8A306)
Modem Firmware: 05.13.04
Unlocked: Yes (Will defo need whatever I update to, to 'hacktivate' it somehow too as handset from Canada, I'm in UK)
Jailbroken: Yes (Can't remember how)
Computer OS: Windows

So I would like to go the latest firmware possible on my iPhone 3G (untethered if possible). There seems to be soo much information and software out there I havent got a clue what or where to go.

Help me please... Thank you in advance

Ok. As you have a 3G, you can go to iOS 4.2.1 and jailbreak/unlock untethered.
You have one problem: Your computer OS - the best (really the only) solution I recommend is to use Pwnagetool Custom IPSW on a Mac running OS X. There is no supported or recommended solution for windows.

The reason why I suggest pwnagetool is that it will preserve your baseband/Modem Firmware at 05.13.04
All other solutions will update your baseband to a higher version and to then be able to unlock, you will need to then use a special trick (update to iPad baseband) which has some serious negative side effects

See
iClarified - iPhone - How to Jailbreak and Unlock Your iPhone 3G Using PwnageTool (Mac) [4.2.1]
Skip the Cydia settings section and the Custom Logos Settings section, they are not necessary.
iClarified - iPhone - How to Unlock the iPhone 4, 3GS, 3G Using UltraSn0w
iClarified - iPhone - How to Hactivation Your iPhone Using Subscriber Artificial Module (SAM)

If you have a friend who can make the custom IPSW for you, you can restore it onto your iPhone using windows via this procedure:

iClarified - iPhone - How to Jailbreak Using a Custom Restore IPSW and RedSn0w (Windows)

Do NOT blindly download pre-made custom IPSW from the web, this is piracy (illegal distribution of copyrighted apple binary files) and you simply cannot trust the person who made the custom IPSW used the correct settings, or even used the right tools/patches. It is also possible that they can include malware, viruses.

You should also check what SHSH you have saved using The Firmware Umbrella - TinyUmbrella as you may not be able to restore back to iOS 4.0.1 or even 4.1 due to the SHSH restriction system Apple introduced to the 3G with iOS 4.0 (you can always restore to iOS 3.1.3 and lower)

Olethros - Thank you soo much for your in-depth reply. I will try and get access to a friends Mac to create the custom IPSW and let you know how I get on.

Thanks again