I installed the same XAMPP 1.6.6a on 2 different machines. On one, my config.inc.php file is 2KB and 1 (long) line of text. On the other, it's 39KB and about 800 lines!!
It's clearly the same file to begin with, but I'm baffled as to how the last one shrank, especially as I've now downloaded & installed it several times, with the same result!