found an old school solution to this problem:  Move the entries for c:\php\;c:\php\ext\;c:\mysql\bin\; to the very start of the PATH variable.  In the dark old days of DOS before Windows I remember often having to reorganise items in the PATH to get stuff working! I had a problem with the gd and mysqli mods on my PHP5.2/Apache2.2/Windows 2003 server. Even after enabling the options in the php.ini file and restarting the Apache service, the mods still would not load. I even tried to restart the Windows 2003 server that php is loaded on - and no go. After reviewing the system path variables in Windows, I noticed that the c:\php directory was set in the path variable, but not the folder for the gd, mysqli and others mods. So I added c:\php\ext to the path variable and rebooted the server. THAT FIXED IT!! After upgrading to PHP5 with Apache 2.2.10 on windows server 2003 I was having troubles with the error saying Fatal error: call to undefined function - mysql_connect(). I had done everything I could think of or find on the internet and was still having the same error show up. I then ran the phpinfo() function and it showed I was reading the correct php.ini from my C:/PHP/ path and it showed a mysql version. The problem was it loaded the mysql files in my system32 directory which were from an earlier version. I simply removed these files from my system32 directory and it had fixed the problem