yousra said:
My i phone already jailbreaked i want to update the software
Are you wanting to jailbreak after updating?
You cannot update, and keep the jailbreak. Updating will unjailbreak it.
Either way, this is how you must update:
Download the 5.1.1 iPSW file for your *device model* here:
http://theiphonewiki.com/wiki/index.php?title=firmware save it to your desktop.
Before doing anything...you should transfer data to computer (since you won't be restoring from a backup...you can if you want...but...I don't recommend it. This is important because your latest backup is from a jailbroken device..not good. You have been warned).
Plug in iPhone, open iTunes.
Right click on devices name,
Click "Transfer Purchases".
Now *shut down device* and enter DFU mode.
Hold down the shift key on your keyboard..and simultaneously click the "Restore" button.
Locaete and double click on the 5.1.1 iPSW.
Let iTunes do the rest.
Once restore is complete, *setup as new*. NOT from backup.
Jailbreaking is a whole process on its own..and should be domes directly after initial on screen setup.