How to update iPhone4 4.3.3 (4.10.01) & 4.3.5 (4.10.01) & 5.0 (4.10.01 preserved from 4.3.x) without updating Baseband - Redsn0w 0.9.10b2 :
Step 1: Connect your iDevice with your PC via USB and open Redns0w you just downloaded above.
Step 2: Start Redsn0w, press on "Extras" > "Custom IPSW" and then point Redns0w to iOS 5.0.1 ipsw firmware that you downloaded above.
Now Redsn0w will start cooking your custom iOS 5.0.1 ipsw firmware
Step 3: Click on "Pwned DFU"
Step 4: Now make sure your device is both OFF and PLUGGED IN to the computer before you click “Next”. (It is advisable to have a AT&T or orig Carrier locked sim already inserted at this point)
At this stage you will be presented with a screen where you will be guided on how to enter DFU mode. Quickly hold “Power” button and then while holding the “Power” button, you will now have to hold “Home” button too. Now after few seconds release “Power” button but keep holding “Home” button until installation begins.
Step 5: Open iTunes 10.5x then Restore your iPhone 4 to the Custom iOS 5.0.1 ipsw (the file name begins with NO_BB).
Step 6: Once your device is up have it activate with the AT&T or Locked Carrier sim if needed
RedSn0w win and mac here:
Win:
https://sites.google.com/a/iphone-dev.com/files/home/redsn0w_win_0.9.10b2.zip?attredirects=0&d=1Mac:
https://sites.google.com/a/iphone-dev.com/files/home/redsn0w_mac_0.9.10b2.zip?attredirects=0&d=1Get Firmware from here:
http://www.limera1n.cc/p/download-ios-ipsw-firmwares-files.html
