I was puzzled when trying to install SharePoint 2013 in Windows 2012 R2. For the past few months when I was doing the same steps, this error did not occur.

If you have done Prerequisite Installation and trying to install SharePoint 2013, You MAY encounter this error message

Setup is unable to proceed due to the following error(s):

This product requires Microsoft .Net Framework 4.5.

Having checked in your registry stated here, my .NET framework was 4.6 (huh? isn’t 4.6 is better and higher version than 4.5 that’s required?)

Yea, so the installer does have a little issue if we have Higher version of .Net Framework.

Resolution

They underlining issue for this is that the Windows 2012 R2 provisioned is pre-installed with .NET Framework 4.6

To undo this 4.6 version, you would have to go to your Control Panel and uninstall the KB3102467 Windows Update