I have the same problem with the php.ini extension_dir setting being overwritten. I tried uninstalling the .msi version and intstalling the zip version in C:\php531. phpinfo() shows other changes I make, but the extension_dir value is always changed back to "C:\php5".
I don't really care if Windows wants to override the extension_dir setting as long as I can still load extensions. So added a C:\php5 directory, put it in the path variable and copied all of the C:php531\ext dll files there. I added the lines "[php_XSL]" followed by "extension=php_xsl.dll " as a test, expecting to see a listing for PHP_XSL appear in phpinfo(). There is no sign of the XSL extension, so guess it was not loaded.
What should I try next?
Thanks for any suggestions.
Bob N