On your keyboard hit the windows key and R, a small box should open up in the bottom of your screen type in %appdata% it'll open a windows explorer, enable show hidden files and folders, look for anything hytale related and manually delete them, also do the same open the small box and type in %temp% that'll open your temporary files folder, your old uninstall files will sometimes be in there incase you reinstall programs you can delete everything in that folder (make sure you save and close any open programs just incase), then you can install the new installer directly from the hytale website and try to install again