HD movies after moving iTunes to a new computer

I purchased a few HD movies on the Apple TV, but the HD versions do not show up in iTunes (although I see the HD files in the iTunes folder on the hard drive).

I had to move everything to a new computer, and now that the Apple TV has synced to the new computer, I cannot access the HD movies because they are not showing in iTunes.

Here's the Question: How can I get iTunes to recognize the HD versions so they will sync to the Apple TV???