hours needed to restore iphone 4, ios 7.1

Dear Sir. My Iphone 4, ios 7.1 was excellent until I got a message from my Itune 11.1.5 telling me that there were some items missing. Would I like to restore my Iphone? of course the reply was, yes. And I started the process but it took lot of time that made me believe that my Itune was not working so I unplugged the device, it was terrible! Now where I am talking to you the device has been plugged for 5 hours but no signal for the end. That is why I asked you dear fellows, how long should it take me to restore my system? Bearing in mind that I have many apps therein, if I lose them that will be disasterous and I love Apple I do not want to leave it. Thank you.