Infamous Already installed error

I have the “already installed” error when trying to login to my wordpress locally hosted site.

It is a locally installed site so i have conplete control over everything from mysql to ftp to ssh.

Installed wordpres and worked a treat.
Tried to move to network setup could not get it working thought oh well ill go back to simple install.

Deleted everything and i mean everything
Database dropped
Folder(s) deleted
made sure any .htaccess files were detleted.
Made sure re-wrire mode was turned off
(no longer need it if not using multisite)

Scanned googl and this site for help
Lots of people have this issue but i can t find an answer that works for me

As i say i have tried delteing everything and downloading, unzipping files. recreating wp-config.php and database and sql user
Tried using different nams for database and user
Changed the Databaase prefix from wp_ to anything else

When i re install from scratch the sites loads and builds the database no errors. create new site with different site name, create aaccount. try and login with account and i get the “already installed error”
If i click login again but dont login and chosse “back to mysiteurl”
i am logged into my site.
If i then click anything else but dashboard the site behaves as expected. If i choose dashboard i get “already installed error”

Driving me crazzzzyyyy

Any ideas please

Thanks