uninstall/reinstall

I know there are many threads for this already, but I have searched and searched but can’t find one that works for my situation.

I had wordpress working fine for 1 domain on 1 account. Now I have 2 domains and wanted 1x wordpress install to run them separately, which I read was possible by changing the config.php.

The Problem:
Stupidly I deleted everything from the root dir except a log folder I don’t access rights to.

I use 1&1 as my host and deleted the database from MySQL administration but after uploading WP, install.php says I have a previous installation still active.

Please help me dig out my previous insstall, and reinstall WP.