Read this... it seems daunting at first but thanks to the good work of the authors it really isn't a big deal. I do think, though, that your "ghost" device may still need to be powered off... read through the directions and see what it says.
Win10 will work fine. SiLabs software is free. Stick is $20. Enjoy!
Whenever I try to include a z-wave device and it fails I immediately stop and focus on getting rid of the ghost I just created before I proceed further. It's a pain but it will prevent the issues you're seeing.
Happy ghost busting... feel free to reach out if you have questions.
