could not be updated.an unknown error occurred (4000) what is this problem
for new update for my iphone error with itunes from my windows compuer
Windows, Windows 10
See If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support. If you're trying to update using iTunes try over the air instead, or vice versa.
Note if you're getting a -4000 error when updating from iTunes you need to disable Find My iPhone, update, then enable again afterwards.
tt2