iphone-hacks.com

Required Files:
iPhone Unlock Toolkit
iTunes v7.3.0.54

NOTE: You do not need to plug your iPhone in until after you have successfully run the iPhone Unlock Toolkit.

So a while back DVD Jon cracked iPhone activation on a windows pc.  While his instructions weren't that obvious without knowing about hex editing some cool GUIs sprung up to make things easier.  But if you updated your iTunes beyond v7.3.0.54 (like I did) you may have noticed that the "iPhone magic numbers" provided by DVD Jon were no longer valid.  While writing this article iTunes is currently at v7.3.2.6 luckily apple still has the old version of iTunes still available for now, in case they take it down we also have it mirrored see the link above.

If you already have iTunes v7.3.0.54 installed you can simply run the iPhone Unlock Toolkit.  If you don't it should spew out an error message that says "Check iTunes version (3.70.0.54) Failed".  This means you need to downgrade your iTunes (or upgrade if you have a really old copy).  To downgrade iTunes simply go to:

Start-->Control Panel-->Add/Remove Programs
Select iTunes and click uninstall

You will need to reboot your computer of course to complete the uninstall.  Once you've done this you can simply install iTunes v7.3.0.54 as you normally would.  After this is done you are ready to run the iPhone Unlock Toolkit.  If you are using vista you must run this as an administrator (right click on the program and select 'run as administrator') as it will edit the iTunes.exe file.  If you receive an error message stating "iTunes must be closed" it means the program is unable to write to the file.  You could also try directly changing the file's read/write access restrictions but using administrator worked fine for me.

After a successful run the iPhone Unlock Toolkit should read:

Check iTunes (3.7.0.54)...
Done.

Unlocking iTunes ...
Done.

Preparing ...
Done.

Connect iPhone to your computer again and it'll be unlocked.

I then plugged in my iPhone, oddly my iTunes opened and then crashed with some windows error that I couldn't duplicate.  Simply open iTunes again worked fine and activated my phone.

It has been confirmed that you can upgrade to iTunes v7.3.2.6 and iPhone v1.0.2 after you have activated the iPhone.  All the SIM unlocks are reported working with these updated versions as well.