Q:

How do I migrate Web sites from IIS 7.5 on one machine to IIS 8.5 on a different machine?

Good day
My self-imposed task is to migrate my small Web sites onto a brand-new machine.
I am looking for some input, on what would possibly be the most sensible way to move these Web sites' relevant IIS settings onto the other machine. 
(The network part is not an issue, just forwarding to a different IP and telling the firewall should be no problem.)
Source system has IIS 7.5 on Win 7 Ultimate.
Target system has IIS 8.5 on Win 8.1 Pro.

What doesn't work, most likely due to the different IISs, is the following approach. On current machine:
appcmd add backup "backup name"

and on new machine:
appcmd restore backup "backup name"

This smashed in two the whole tree (I should have saved the target machine's empty IIS state, of course). This is easily fixed, though: from Windows Features, disable IIS, let the PC restart, and enable IIS again.

A:

Backup and restore has been designed to be a machine local way of managing IIS configuration. One backup saved from one machine cannot be restored on another machine easily.
Microsoft does provide a tool for users to move web sites from one IIS machine to another, which names Web Deployment Tool,
https://www.iis.net/learn/publish/using-web-deploy/synchronize-iis

