iTunes won't recognize my phone

[RedWritingHood]

Hi, sorry to barge in with a problem, but I looked around and haven't found a solution to my problem.

I have a 3G that I just tried to sync with the newest version of iTunes, however, I am presented with this message:

This iPhone cannot be used because the required software is not installed. Run the iTunes installer to remove iTunes, then install iTunes again.

Even though I have done exactly what it says, iTunes still will not recognize my phone. All of the information in my iTunes account is gone, except for my name at the top of the page.

Thank you for any help. I really appreciate it