i tried every combination much like you, till running across this page.. however, i still needed to copy the libmysql.dll to c:\windows\system32 to get it to work... the great thing you page made me realize was to stop using the copy i had gotten from another site and get the one from the php zip file... that was the big fix for me on Vista Home Pro SP1 + PHP 5.2.6 + (fixed it for Apache 2.2.9 and for IIS 7)