freezes when i try to open preferences

I upgraded to the newest version of iTunes (Windows 7; Internet Explorer). My iPhone isn't being recognized so I am following the troubleshooting section of support to attempt to fix this issue. I now have another one--I want to back up my library to my external hard drive. I am trying to open Preferences (part of the backup instructions on iTunes support) and every time that I click on it, iTunes freezes. I have tried the "Troubleshooting unexpected quits, freezes, or launch issues" article to no avail. Any suggestions?