Rec Boot has very simple interface, only two buttons i-e "Enter Recovery Mode" which puts your i Phone to recovery mode and "Exit Recovery Mode" which takes your i Phone out of recovery mode option.
The program requires Lib USB utility whos setup is included in the zip package.
Step 7: Switch your i Phone 4S off after 20-30 seconds and then turn it back on.
Step 8: When you see a signal bar, press Use Cellular Connection. Insert your T-Mobile SIM once again, and your i Phone 4S should be unlocked.
But it seems that the situation with the freshest Apple smartphone, the i Phone 4S, is different.
An unknown hacker released a method that allegedly allows for unlocking Apple's latest device without any modifications in software or hardware.
Update#10: Download Tiny Umbrella (Fix Recovery) to fix i OS 4.3 (NOT i OS 4.3.1) recovery mode loop issue.It is unknown yet whether the exploit will work on Apple’s devices with a dual-core A5 chip like the i Pad 2 or the latest i Phone 4S.At the moment, i OS 5 can be tethered jailbroken using Redsn0w, Ac1d Sn0w or Sn0wbreeze.Manual method to put your i Phone into recovery includes the following steps: Download Rec Boot application for Windows Download Rec Boot application for Mac Update#1: Fix i Tunes 1015 Restore Error with Rec Boot During i OS 4 Downgrade Update#2: Windows 7 and Windows Vista (64-bit) users can follow this tutorial to install Lib USB without any issues. Update#7: Download Rec Boot 2.1 for Mac OS X 10.5.x and above.Update#3: Now you can also use Tiny Umbrella to kick your device out from recovery mode. Update#8: Download Rec Boot 2.2 for Mac OS X 10.5.x and above.If you want a semi-thered jailbreak on i OS 5, you should install the Semi Tether patch from Cydia.And those of you who are running i OS 5.0.1 can use Redsn0w or Ac1d Sn0w to get a tethered jailbreak.It is worth noting, however, that the solution that Pod2g developed confirmed to be effective only for i Phones, and i Pads equipped with an A4 processor like the first-gen i Pad, i Phone 3GS, i Phone 4, and Apple TV.i Phone owners who rely on the Ultrasn0w unlock still should be cautious with upgrading to retain the unlockable baseband.But if you are interested, you should keep reading.Step 1: Place your AT&T SIM card into your i Phone 4S, it I's not there already.