After updating to iTunes 11.1.2 constantly hanging then crashing

I am no longer able to use 64-bit iTunes at all on Windows 7 64-bit. I downloaded and installed the latest version and now cannot access any of my content. I am constantly receiving "Unable to load class data" errors, then iTunes hangs and eventually crashes. I occassionaly receive messages that the "Bonjour Service" is not running, but when I go to the Services Console, it always shows Bonjour as running. I need assistance immediately. I am even willing to pay for support but cannot even find a phone number nor email address to obtain such help from Apple. I have reset, uninstalled, re-installed, and repaired iTunes with no success. Please, somebody HELP!

Regards,

PassGo

(Lon)