by Ryan Marshall.
Sorry Forgot I'm using , Windows 2008 Server, IIS7.5, PHP5.4.31, MySQL 5.6.17 (fresh install on a new machine) Installing Moodle 2.6.X
I double checked, the extension=php_mysqli.dll is uncommented
File php_mysqli.dll is in the ext directory
I have even restarted IIS
I'm still getting that error.