What files do I need to save to reconstitute PHP, ZDE, MySQL and Apache when I reformat my hard drive? It was hard getting them working right and I've been dreading a needed wipe of my drive for that reason--but I gotta go ahead.
For PHP you need the php.ini file and Apache needs the httpd.conf file. Remeber, when you reinsall both php and apache - if the release that you download is newer then the old one DON'T replace the files - use the to make sure that you use the same values.
When it comes to MySQL, you need to "download" your databases, tables and the data in the tables. Download MyPhpAdmin - there you got a function where you can download all your data. You can also take a backup of the my.ini file!