I'm installing v14 in my test environment which is a domain network (no Exchange) on a new VM joined to the domain which has IIS already installed but when it comes to selecting which web server to use, the options are greyed out and ABYSS preselected. I wanted to use IIS. Any suggestions as to why it would behave in this way and how to get around it? Update: I've attempted the same install on a different VM on a different hypervisor on a different network connected to a different domain (still 2012R2 with IIS installed) with exactly the same results. Can't select IIS.