So recently iOS 5.01 was released by apple and a few weeks later an untethered jailbreak of this firmware was let loose into the wild. I’ve personally tested this method and it works great and gives the functionality of iOS5 to the jailbreaking community. I have embedded a video and also a picture how-to below:
These are instructions on how to perform an untethered jailbreak of your iPhone 4 (THIS WILL NOT WORK ON NEWER A5 DEVICES SUCH AS THE iPHONE 4S) on 5.0.1 using RedSn0w for Windows.
NOTE: This procedure will cause you to upgrade your baseband potentially ruining your chances for an unlock!!
Create a folder on your desktop called Pwnage
Download the latest version of RedSn0w from (redsn0w_win_0.9.10b3) and place it in the Pwnage folder. Likewise, download the 5.0.1 firmware from (iPhone3,1_5.0.1_9A405_Restore.ipsw [GSM ONLY]) and place it in the Pwnage folder. (Note: you do not need to download the 5.0.1 firmware if you are already on iOS 5.0.1)
iTunes will now update your iPhone to the new firmware.
**Windows 7 users may want to try running the redsn0w executable mode as an administrator in Windows Vista compatibility. You can do this by right clicking the executable and selecting Properties from the contextual menu.
RedSn0w will now guide you through the steps to get into DFU mode. You can find more help with DFU mode here