Sorry I didn’t mention that. Yes, I did tick it on and off multiple times on both users, logged out, cleared the cache, logged back in and nothing. Logged out and back in as the other user and still nothing.
I had already reinstalled from the admin dashboard several times before posting here.
I did deactivate the plugins via ftp as described. By doing that, I got the default visual editor back in a very basic form, but not the html tab. TinyMCE plugins do not seem to work however. This is all on the twenty eleven theme.
Do you think that another install via ftp would make any difference?