First off: I don't have any plug-ins installed, neithe do I have any theme installed. This would mean that I had a working WP environment anyway.
I have ordered my host to delete my complete hosting package.
Then I did a clean installation of WP 3.0
Of course I restored my database through CPanel.
I gave it the same DB_name and User_name as it had in the past.
When I run install.php in the wp-admin directory I get this message:
Can’t select database
I read many threats on this an didn't find an answer.
I followed the prefix advice and read the documentation here:
http://codex.wordpress.org/User:harkey/Database_Errors
I replaced the quotes with double quotes.
Nothing helped.
Is there a wizzkid out there who can apply some magic?