I'm doing a trial run of multisite on a HostGator account before setting up a new installation for a school. The school site is already using a subdomain, so I want the teachers' individual sites to be in subdirectories. I didn't see this option but achieved it in the config by setting subdomain_install to false. This is my second try; the first time I got the Super Admin option, but adding a site created a subdirectory, which surprised me as WordPress has been sitting on the domain for a year or so. So I started over, after deleting the extra tables in phpAdmin so that the installation wasn't telling me that it was already set up for a network.
The problem may be in the username. From another topic here, I saw you ask if there were capital letters in the username. Somewhere along the way I changed "admin" to "Heather", and now there is no "admin".
Can I add a super admin directly to the database? Or should I start over yet again?
The site is at http://www.com-info.ca. I'm running it in French, but hopefully you can find your way around.