I purchase a TV show in HD, but it came with the non HD version. Because it was faster to purchase, I did the non HD version first, just so I could watch it. The HD version never fully purchase, and now my Itunes wont purchase the rest of the season because it says my disk is too full. I can not seem to delete the HD versions, I assume because they haven't finished purchase. The regular versions I backed up to a disk, but I delete them, and Itunes puts them back, I delete it in the purchase page, in a play list I can still play it. If I plug in and sync my ipod, the episodes that I "deleted" are back. The don't show up in my recycle bin, and I cant click and drag them to it either. At this point, I don't even care if I loose the HD version, I want the files off my computer.

Select what you want in the Library and hit delete or Edit>Delete.

Also disable automatic sync for your devices, manage manually instead, then go to your iPod (though iTunes) and delete that way. Also disable auto "check for purchase".

If your Trash gets filled, empty it.

After deleting everything you want, restart iTunes.

It's best to keep your computers hard drive less than 3/4 full, ideally less than 1/2 full for best performance. So offload your unused files to another drive or DVD's/Cd's.