I'm trying to update my sisters iPhone 5 to the new iOS update but it's asking for the passcode to do the update. We have tried the passcode to unlock the phone and all the other passcode she can remember but we're still unable to update. Last time we had to use iTunes and then reinstall everything but that took forever to do. Is there anyway of resetting it? I've tried checking the restrictions thing - it's already turned off as well.
The only password that gets asked when updating directly on the phone is the password you need to unlock your phone (or need to enter after restarting your phone). If she doesn't remember any of them, you must fully restore the phone through iTunes.
iPhone 5's are unable to receive iOS 10.3.2 and later. Apple dropped support for 32-bit devices with 10.3.2. Remembering the passcode is irrelevant here. I was wrong. 10.3.2 isn't out yet :P
See if this works:
Go to iTunes and plug in your sister's phone. (Optional but recommended in case anything goes wrong: make a backup of the phone)
When you see the summary of the phone, see if it says "iPhone5,1" or "iPhone5,2".
Go back to iTunes and shift (or option)-click on "Check for Update..." and select your downloaded IPSW.
Unlock the phone if it isn't already.
Wait for it to update!
If this doesn't work, then I don't know what to do. Hope this helps! :-)