Install PHP 5.3.3 on WAMP
The latest PHP version provided by WAMP is currently PHP 5.3.1. Continue reading if you want to install a later version.
I successfully installed PHP 5.3.3 on my WAMP server under Windows 7 64 bit. But this short tutorial will probably work on other versions as well.
Go to the Windows download page at PHP.net and download the desired version. You must select the ZIP VC6 x86 Thread Safe variant.
Unpack the contents to the PHP bin directory in your WAMP installation. I unpacked PHP 5.3.3 in C:\wamp\bin\php\php5.3.3\.
You should now copy the following files from the php5.3.0 directory, to your newly created directory (php5.3.3 in my case): php.ini, phpForApache.ini and wampserver.conf.
Now we just need to make a quick edit in both INI-files. Search for "5.3.0" and replace it with the PHP version you are installing.
Save the files, and you should see the new version in the PHP version menu in WAMP. If not, right-click the WAMP icon and choose "Exit", then start it again.