Because of security reasons suggested on the zencart website, I tried to rename the admin folder.

It resulted in a complete failure. I can as of now neither log in to my admin, or even visit my zencart shop.

Here is:
My webhost had installed the Zencart to me, meaning the folders looked like this: www.mydomain.com/zencart/admin

When I changed the admin to a secret new admin name, of some reason mutliple of files whent to different folders, namely two. Admin folder and the new admin-secret-name folder.

I have now tried to transfer the classic default zencart, hoping it to owerwrite, replace and fix it, but to no vain.

Error messages are like this:
When trying to log in to my admin it, this comes up in the browser:

0 DB_ERROR_NOT_CONNECTED
in:
[select * from zen_project_version WHERE project_version_key = 'Zen-Cart Database' ]
If you were entering information, press the BACK button in your browser and re-check the information you had entered to be sure you left no blank fields.

And error message when trying to visit my zencart shop, the address field in the browser reads like this:
http://www.mydomain.com/zencart/nddbc.html

And in the browser window this error message comes up, it reads like this:
Sorry!
There seems to be a problem connecting to our database. Please give us a few minutes to remedy the problem. Thank you.

To verify the site status ... Click here

Any ideas?

Or do I simply have to delete the whole store from my webhost, and then reinstall a clean default zencart and do all my work over again?

Thanks in advance
Stefan