Imagine for a moment there's a network setup with 4 or 5 sites on it.
Then one day "something" happens and it's not a network site anymore. The main site is set up to be standalone. The sub-site database tables are there, but not hooked up.
The site owner doesn't notice for weeks or months, then one day says "HEY! We need that all back! Quick!".
This is where I come in, asked to fix things.
I put define('WP_ALLOW_MULTISITE', true); into wp-config and it didn't magically start working like I'd hoped it would.
When I go to Tools->Network setup it says this is a new network on an old install, so I can only do subdomains.
The other sites were NOT sub domains, so I need to do something different.
What are my options here?