Below are 5 easy steps to installing and testing the Apache Web server, MySQL database and the PHP programming language on a Windows machine currently running IIS—and want to keep IIS working!
If you're running a Windows computer and use IIS to host websites, and want to host websites also on the Apache server, the steps below should accomplish this in about 30 minutes (based on Internet and computer speeds). And if you have problems, you can always uninstall WAMP and remove the remnant "C:\wamp" directory, and you'll still be way under the time you'd have to filter through the plethora of instructional websites.
NOTE: It becomes general maintenance over time to have to uninstall and reinstall WAMP due to some conflict due to Microsoft downloads. In this case, it's good (and will save time in reconstructing) to make backups of the “www” (C:\wamp\www) and “data” (C:\wamp\bin\mysql\mysqlx.x.x\data) directories, and just re-add those directory files back into the newly created directories after reinstalling WAMP.