mate if you need a hand with bug fixes etc let me know!
EDIT: thought you could benefit from abit of my code. heres a version of your tool i made from scratch with no bugs so far.
i suggest you review the code and see if you can fix your version
oh and its alot quicker
source code: https://github.com/Ricky310711/Quick-ADB-Installer
Tried and works fine on Win 8.1 64bit. thanks !