Upgraded from Pro Tools MP9 to Pro Tools 10. Any way I can revert back?

Is there anyway I can go back to Pro Tools MP9 after upgrading to PT10? I upgraded to PT10 from downloadable software. Pro Tools MP9 was software that was purchased, but I'm not sure if it is possible for me to somehow get my PTMP9 ilok license back now. PT10 has given me almost no reasons to want to keep it. It has given me nothing but problems thus far, when my PT9 setup was almost flawless. I only updated to be able to use my MeldaProductions plugins. I can't even get playback on PT10 today after updating drivers to my setup yesterday. It's my fault though, as I had never learned that Pro Tools 10 was pretty much not officially compatible with Windows 8.1. I just want to go back to Pro Tools 9 now.