I struggled with this for hours, and as with most things to do with code and web syntax it was something really stupid that caused the problem. I had moved my site from one host to another by:
- Backing up all of the content files
- Backing up the SQL file from the database via phpMyAdmin
- Moving all of the content files onto the new server
- Creating a new database with matching credentials
- Changing the DNS settings to point the domain to the new server
All should have gone well, but the site kept directing me to the fresh installation page. If I filled out the install form, it would create a whole new set of duplicate tables in the database and leave me with a brand new installation, not my old one. After copious amounts of research, this is what solved my problem:
- In the Structure menu of phpMyAdmin, check all of the tables and then from the drop down menu select "check tables"
- If there are tables that need to be repair, select them and choose "repair table"
- Finally, double check everything in the wp-config.php file. This is where I found an error with the table prefix. It was almost insignificant, but the additional characters that were probably due to sloppy copy and pasting on my part were responsible for the redirect to the install page.
Hopefully that helps!
(This was a helpful and simple guide to moving my site from one host to another from Jason Bobich.)