Well my friend, if you deleted the byteball directory in program files, you deleted the wrong folder. Please try to uninstall byteball wallet by the usual way.

You have to delete the folder with the personal local data, which also includes your wallet details. This directory can be found in:

C:/Users/YOURNAME/AppData/Local

The AppData directory is invinsible usually, so you have to change the options for displaying hidden directorys.

If you found the directory Local in your AppData directory, you will find another directory called byteball. You have to delete this one.

After you can reinstall byteball wallet and you will be able to select the smart version. I hope this explanation is detailled enough. If not, im sure we will solve your problem ;)