Apache 2.4.10 win32 from apachelounge with php 5.6.4 VC11 x86 Thread Safe on windows7 sp1.
The 5.6 Thread Safe (TS) x86 mongo.dll i downloaded from http://pecl.php.net/package/mongo/1.5.8/windows
I kept getting the following error
PHP Startup: Unable to load dynamic library mongo.dll
The specified module could not be found.
I fixed this by adding the php and the php/ext to the windows path and rebooting(log off didn't cut it).