Iphone 3gs IOS 5.1 with or without baseband 6.15 untethered jailbreak

Untethered jailbreak is only available for those who have OLD bootrom. (for now)

Things we need.

1. IOS 5.1
http://www.felixbruns.de/iPod/firmware/

 2. Redsnow.( i dont prefer snowbreeze.<-- have many bugs on ios 5.1) link:  redsnow


 step 1.

boot your iphone 3gs to DFU mode.

Then Run redsnow. choose Extras and choose PWNED DFU.

next one. Choose custom IPSW and select your newly downloaded IOS 5.1 IPSW.

after that you will see another IPSW with username: NO_BB_XXXXXXX

then restore it using Itunes. hold shift and click restore. Choose the NO_BB_XXXX.IPSW

wait for it to finish.

After that boot again to DFU mode.

open redsnow. Choose "Select Ipsw" choose your Downloaded Stock IPSW.

go back. click JAILBREAK.

There will be other options. Just choose "INSTALL CYDIA"

Then you have your untethered Iphone 3gs Running on IOS 5.1