Few things you need to know before beggining to test : Windows 2008 R2 is and will remain only 64bit OS. XenApp 6 can be install only on Windows 2008 R2.
I begin this insallation on a clean naked Windows 2008 R2 without any update. You can check teh system requirements here : http://support.citrix.com/proddocs/topic/xenapp6-w2k8-tp/ps-system-requirements-w2k8-xa6.html
First, few screenshots of the new installation interface to describe the installation process.
DotNet 3.5 Sp1 is updated as soon as the installation beggins, after a new white interface very easy to understand popup and you can choose between reading some more information about what you’re going to install or adding roles to your server.