Problem updating iphone 3gs to ios 5
Hit the Ok button; Now hold down the shift (Windows) or Alt/Option (Mac) key and click on Restore button.
You don't need to go into any mode just option click restore then select that ipsw.
***Do NOT select the stock i OS IPSW or you’ll lose you unlock*** Once the restore process is complete, your i Phone 4/3GS will have a preserved baseband and now ready for the jailbreak and then unlock with Ultra Sn0w; Now you can unlock your i Phone 4 or i Phone 3GS with Ultra Sn0w or Gevey SIM on i OS 5 firmware; To jailbreak i Phone 4 or i Phone 3GS on i OS after preserving the baseband, Follow this: (how to jailbreak i OS with Red Sn0w) guide from Step 3.
After jailbreak, here’s How to Unlock i Phone 4, 3GS i OS 5 with Ultra Sn0w.
You can follow us on Twitter, Google Buzz, Facebook, and Subscribe to RSS Feed to receive latest updates.
But at the same time, new software updates promise all kinds of cool new features. So it makes sense that i Phone 3GS users, who aren't ready to upgrade to the i Phone 4S, would want to update their phones with the new software.