There is an issue when trying to install Kentico 7 using the new installer (there is also a classic installer), where the wizard will not see that you have an IIS 8.5 server running and it will not list the existing websites.
This specific scenario will only happen when trying to install in a spanking new Windows Server 2012 (R2 or not).
You may find the following article in the Kentico knowledgebase Kentico 8 Installer doesn’t detect already installed IIS (8), but it would not solve you problem with the Kentico 7 installer. Beside, in my experience, the Kentico 8 installer was working flawlessly and not showing this issue. Unfortunately, due to business requirements we needed version 7.
The reason for this issue, is because this version of Windows, by default, have installed .NET 4.5 only. After you install .NET 3.5, you will see that the installer works like a charm.
You may also want to make sure you meet all the other required components. You can find them in this MSDN article recommended by Kentico’s support in their discussion forums. Just remember to add .NET 3.5 to the list.