I uninstalled (then manually removed the install folder which was still full of stuff), and reinstalled into a different folder. It works ok now. Go figure.
Note that both the original (broken) and new installs were NOT into any Windows directory (Program Files, etc.). In fact, both installs were onto a different physical drive (i.e. D: not C)
But I did have the following observations:
1. Uninstall does a poor job of uninstalling. Game files, etc. were left behind. Should be fixed.
2. After uninstall (and deleting the original install folder) when reinstalled (into a different folder), it still magically knew my access code. Again, IMHO, this is a shortcoming of the uninstall process.