My iPhone won't connect to iTunes

My iPhone won't connect to iTunes. Help?

Added (1). My IPhone, when I plug it into my computer, only shows up in 'documents' and won't come up on ITunes. This has never happened before.

You may try these steps.
1. Update iTunes to the latest version. Plug in your iPhone. If iTunes still can't recognize it, then in iTunes in the top left corner click help> run diagnostics. On the box that comes up, check the last two things. Click next and it should identify your iPhone.
2. Click on your windows start menu. Type in "services". Click on it and when it pops up, on the bottom of it click on "standard". Now Scroll down to find "Apple Mobile Device" Right click it when you see it and click on "Start". When it has started, close iTunes and replug in your iPhone and it should show up.
3. Check the USB cable
4. Verify that Apple Mobile Device Support is installed
5. Restart the Apple Mobile Device Service and verify that the Apple Mobile Device USB Driver is installed.
6. If you just want to add some photos, songs and movies from computer to your devices, you can use an iTunes alternative to do the job
http://www.reviewstown.com/itunes-alternative.html
7. Check for third-party software conflicts.