Windows Server 2012 does not add the role, why?

Question

DHCP

When adding the DHCP role, after clicking "install" an error appears, saying that the role has not been installed, since the server needs to be rebooted, of course, as it happens with windows, rebooting does not help. But in addition to everything else, the list of roles cannot be loaded, a banal reboot of the server does not help. How to be?

Answer 1

reboot again

Answer 2

Greetings.
And the server a case not svezhepostavlenny?