I will tell you how I recovered my tablet after completely messing it up, this WILL DELETE EVERYTHING WINDOWS AND ANDROID..
Follow this guide from Step 4 – Make sure to download all the required files first.
Download Mirek rom as well, and when you are on Step 8 of the guide, you can point at the Flash ROM (mirek190).json file in his rom folder, this will wipe your tablet completely to factory settings and install the Mirek rom, saving you doing stock, then fixing windows, then applying mirek rom.
Then just carry on with the guide to reinstall windows.
Good Luck