There can be some reasons why you want to reinstall wordpress multisite (network). For example, you decide to change it from sub-domain to sub-directory. Even if you remove all entries from wp-config.php file, it won’t let you reinstall network and will write: “Warning: An existing WordPress network was detected.“.
To remove this message, you have to delete these tables from database (after removing everything from config file):
- blogs
- blog_versions
- site
- sitemeta
That’s it, now you can start installing WordPress network (Multisite) as if it was never installed before :)
Jaroslav's Weblog 
For example, you decide to change it from sub-domain to sub-directory.
You hit the nail on the head! :)
Thanks a lot for the information, it’s been really useful.
Cheers,
Thanks a lot………it has give the right solution for which i was looking from last 5 hrs……….. Thanks Once again
I am trying to install a multisite and am having problems so I would also like to start over. But what exactly are tables and where can I find the files you mention?
Life saver post of the day. Thank you.
Life saver post of the day.
Rock and roll!!!
woow thank you very much :)