My iPhone wont back up because the loading bar wont move?

My ios is 4.3.3 and when I try to back up the iPhone on iTunes it wont work.
I tried deleting the Backup folder in the iTunes mobile sync folder, but it still dosen't work, I waited 12 hours for it to backup.

You might want to try updating your phone first if you can to the latest IOS 6.1.1. Depending on what iphone you have. I'd also try holding the lock button and home button at the same time until the phone shuts off, ignore the "slide to unlock". Just keep holding them, that can solve your problems a lot of the time.