Download the 2.1 firmware:
or for 2g:
install itunes v8 (http://www.filehippo.com/download_itunes/) <-- all versions of itunes are there
Update the iphone with iTunes and make sure it is activated!
Uninstall iTunes v8
Uninstall Apple Mobile Device Support (From Add/Remove Programs in Control Panel)
Install itunes v7.7.*
Download quickpwn with the correct 2.1 bundle inside it http://xpwn.co.uk/quickpwn-2.1-2g-3g.rar
Run quickpwn...select your iPhone1,2_2.1_5F136_Restore.ipsw or iPhone1,1_2.1_5F136_Restore.ipsw
you can select cydia and installer and logos if you wish
When it is finished the phone will reboot...Cydia and Installer will NOT be visible
Download TotalCommander <-- http://xpwn.co.uk/tcmd704a.exe
Download t-pot addon <-- http://xpwn.co.uk/T-PoT.1.1.zip
Install TotalCommander and in the left pane navigate to T-PoT.1.1.zip and click on it. It will install t-pot automatically.
Download the mobileinstallation patch <--
Use Totalcommander to install patched mobileinstallation to /System/Library/PrivateFrameWorks/MobileInstallation.framework ... clickon the dropdown box [-\-] top left and select network neighbourhood then t-pot. Remeber to back up your original mobileinstallation first!
Still in TotalCommander delete /private/var/mobile/Library/Caches/com.apple.mobile.installation.plist
Reboot the phone and all is good!
Thanks to the #xpwn crew...