There are several methods of installing PHP on Windows operating systems. If you have installed PHP as a part of any stack like Acquia Dev Desktop or WAMP, you just need to configure PHP path for that directly jump to step 7.
Step 1: Navigate to website php.net
Step 2: Click on Downloads in top menu
Step 3: Click on Windows Downloads
Step 4: Click on zip link of thread-safe/non thread safe php. Your download will start automatically.
Step 5: Once the download is finished. Unzip folder and paste it to your desired directory.
Step 6: Copy path of file where php.exe is located
Step 7: Go to Control Panel -> System -> Advance System Settings -> Environment Variables
Step 8: In System Variables -> Path -> Edit
Step 9: Click on New and Paste your path and click on OK.
Step 10: Open command prompt and check php installed successfully by typing
$ php -v