1. Stop the WAMP server.
2. Go to website windows.php.net download PHP 5.4 VC9 x86 Non Thread Safe
Do not download the INSTALLER.
3. Create the php5.4.45 folder in wamp/bin/php
4. Unzip the downloaded zip package into the php5.4.45 folder
5. From the existing PHP version file (such as php5.4.45, (eg. wamp/bin/php/php5.3.3)) Copy the following files:-PHP.ini, Phpforapache.ini, and wampserver.conf to the php5.4.45 folder.
6. Open the following files for the php5.4.45 folder:-PHP.ini and Phpforapache.ini and replace 5.2.5 with 5.4.45.
7. Go to Wamp/bin/apache/apache/apache2.2.11/bin to delete the php.ini file.
8. Restart the Wamp.
9. Select the old version 5.2.5
10. Wamp is restarted after selection.
11. You can choose Php->version-> 5.4.45 at this time.
12. Reboot successful. Complete
You have to download the VC9 processor
Wamp Upgrading PHP Version