I read it, but see nothing about JB 2.1 using Windows. And I don't understand/know how to do "custom ipsw".
You need to upgrade to 2.2 in iTunes (not 2.2.1) then you need to download a custom ipsw of 2.2.1 from the internet (google) and then hold shift and click restore in iTunes and click that file. And then you can download yellowsn0w and your device will be unlocked.![]()
Is there any tool that can Jailbreak 2.1 with Windows?