currently SharePoint 2013 is not supported for installations on servers running Windows Server 2012 R2.
If you are on such an environment and try to install SharePoint Pre-requisites you get an really annoying error.
"Application Server Role, Web Server (IIS) Role: configuration error"
Even if you have configured everything yourself the error does not disappear. At this point of installation he tries to execute Server Roles configuration via Powershell.
In the Log File of the preparation tool you will see the following lines, the identifier for the problem is the error Code (2).
If this is your case then you have an not supported operating system installed.
There is no workaround for this problem currently, it will be solved with the release of SP1 for SharePoint 2013, but no release date is announced.
Nov 04 2013, 04:23 PM