I dont know if you fixed, but I tried some stuffs and they WORKED (im so happy):
i just create a usb with media tool from windows, to make sure it was bootable. then i deleted all the files on it and put the files downloaded from teclast website (you can just type “teclast firmware” on google and click on the first result)
took this usb, put into the teclast tablet, launched it (make sure it’s the first bootable media in bios, the key to enter the bios is ESC).
it reinstalled windows with original firmware and everything working
hope this helps
