How do you remove an old PHP installation and install a new one?
Re-installing a php installation be it windows or unix depends on the method it was installed originally. In linux/unix this may be binary or from source and depending on the installation method and the subsequent method of package removal,reinstall should be followed. If the original package was compiled from source,the appropriate compilation options and flags may need to be followed or existing applications may not work.
process for removing:
go to control panel next go to add or remove programes on that select php and click on that then we get remove option click on the remove the old php wll be voillated(removed). process for installing php 5.1& earliar versions: Run the MSI installer and follow the instructions provided by the installation wizard. You will be prompted to select the Web Server you wish to configure first, along with any configuration details needed