Referring following link
http://www.php.net/manual/en/mongo.installation.php#mongo.installation.windows
There are thread-safe, non-thread safe and with this it is also prefixed with VC6,VC8,VC9.
I have window 7 Ent and I am not able to understand which binary (.dll) I should download from here.
How am I suppose to know which dll I have to download ?
How to identify which VC compiler + thread safe or non-thread safe combination to choose ?.
To tell which PHP install you have, from the command line, run this command:
This will dump phpinfo page by page. On the second page or so, you should see a “Zend Extension Build” and/or a “PHP Extension Build” key under the “System” section. Maybe it will display something like “API###, TS, VC9”. TS stands for “thread safe” (which actually also shows as enabled/disabled in the “Thread Safety” key just a bit below that). “VC9” stands for… VC9. You already know you have PHP5.3 installed. This means you want to install the PHP5.3 Threadsafe VC9 version of Mongo.
Also, this is an example of when user provided comments in the PHP manual page are very helpful. Check the first comment by Andrey 01-Jun-2011 11:54.