You can try the following:
Open up the web.config in a text editor and find this tag:
<globalization resourceProviderFactoryType="Kartris.SqlResourceProviderFactory" />
You may actually find two, one commented out, and the other not.
Make sure it (or both, if there are two) is commented out, like this:
<!-- <globalization resourceProviderFactoryType="Kartris.SqlResourceProviderFactory" />-->
Upload this web.config and then refresh the site in a browser. You should find it sends you to the install routine again.
At the db section, it should find the db and recognize that the data is already there. So click to use the existing db. But it should still generate a new admin password for you. Make sure you note it down carefully!