Yep, it stores the file location on disk in the database (somewhere in the wp_options table).
If you’re handy with MySQL you could fix it, but be very careful! It is stored as a serialized php-array so the string length of the path must be specified!
If you have no clue how to edit a serialized array and/or if it’s not a big issue to start all over, you could just remove the plugin, delete the database record with the path in it and reinstall the plugin. (removal does not delete the options)
(to remove the record, some knowledge of MySQL and access to something like PHPMyAdmin might come in handy)
