Are you trying to install VMWare vCenter Server 5.5 on a brand new Windows Server 2012 R2? Is the installation (both manual or simple) freezing on “Installing Directory Services”?
The problem is that the installer tries to run OCSETUP.EXE from within the system32 folder. However this executable is absent from 2012 R2.
Luckily, you can simply copy it from either 2008, 2008R2 or 2012 to your 2012 R2 server.
The file is in c:WindowsSystem32 (assuming that your Operating System is installed on the C: drive, of course).
Now that you have copied the file, from the Server Manager Add the Lightweight Directory Services Role on the server.
Clean up any trails of the failed vCenter Server installation, restart the server and start the process from the beginning.
Should be fine now and you can continue to adding your ESX(i) hosts to the vCenter Server.
If you have any remarks or questions don’t hesitate to write them down in the comments section.