Enabling PHP error logging

Within the PHP directory, open php.ini



display_errors = Off (This will redirect the errors from end users)
error_log = "php_error_log .log"


Then restart the Apache server, you should now find the log file within the PHP folder.

Difference between PHP VC6 and PHP VC9

VC6: Compiled using Microsoft ver. 6 C++ compiler
VC9: Compiled using Microsoft 2008 C++ compiler

Of course VC9 provides improvements in performance and stability.
http://php.net/manual/en/install.windows.manual.php

However, if you are using Apache 1 or 2, you have to choose VC6.