Restore in itunes without updating
Finally, before attempting any of the methods we've highlighted below, we recommend disabling "Find My i Phone" first instead of doing so when prompted to streamline the process and stave off any potential hiccups it may cause.
If an update is available, tapping on Download and Install will finish the process for you with no attachment to a computer and no i Tunes at all. This is by far the easiest way to get the i OS update installed onto a device and requires no computer at all, the whole thing is completed on the i Phone or i Pad.This step by step guide/tutorial will show you how to update your i Phone 4 to i OS 4.1 while preserving the baseband.Because we will not update the baseband, you will still be able to run the latest i OS version available, you will be able to jailbreak using Lime Ra1n, and you will be able to unlock your i Phone using Ultra Sn0w. It is pretty simple but it does require you to read the steps carefully. If you are on Mac, hit the Alt/Option key while clicking Restore.We can't stress this enough — all the methods listed below will not only take off the jailbreak but completely wipe your device and restore it to stock configuration.
It's also worth noting that the last three methods mentioned will update your device to the latest firmware.
You can always download i OS IPSW files without i Tunes, and then update the software using i Tunes itself.