Where do I find the IIS EXPRESS installation files?

You can find it here:

https://www.microsoft.com/en-us/download/details.aspx?id=48264

You can install it on these systems: Supported Operating Systems

Windows 10, Windows 7 Service Pack 1, Windows 8, Windows 8.1, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2

You can run it immediately after downloading and running from your chosen location.

These are the benefits of using IIS EXpress:

• The same web server that runs on your production server is now available on your development computer.
• Most tasks can be done without the need for administrative privileges.
• IIS Express runs on Windows 7 Service Pack 1 and all later versions of Windows.
• Many users can work independently on the same computer.

All information from Microsoft Site.