FYI, unfortunately, I never found a solution and only resolved it by reformatting my laptop and re-installing all of my software, data, etc.
My previous efforts involved everything noted below. I used Revo Uninstaller to uninstall, which (as I understand it) provides a fairly thorough Registry and Folder search to clean everything up. I also did my own search to identify and remove any file and account references as well. None of this was successful.
The point being, everything everyone is saying is reasonable, but still ineffective. Personally, I think this relates to poorly designed software will not work without issues and issues (and their solutions) are harder to trace because of the poor software design. A bit of a cycle.
I wish I had better news.
P.S. Not a solution of any sort to no downloads being available from Ancestry, but FYI, you can copy the FTM CD contents onto your computer and install from there, so you don't need to worry about the CD.