The first novel I ever wrote was a total piece of garbage and never should have seen the light of day.(I bet you hear that a lot...) I decided to take the characters(who I still love dearly) and a few of the basic plot points(ie, pretty much just the main love interest), and turn it into a screenplay. Most of the plot is going to be all changed up.
My question is, does this count as an adaptation? I really am changing a lot, the characters and setting are the same but like I said almost no plot will be the same(I was 12 when I wrote it, all they did was sit around and angst).

If it was never really finished, it's not an adaptation; it's just taking the characters out and playing with them again! There's nothing wrong with adaptations though--they're totally allowed (especially when you're adapting your own work!)