Unable to install DHCP server role on Windows 2012 Server Essential.
When you try to install the DHCP Role on a windows 2012 R2 server, then the role installation might just stop with the error "0x800f0922".
Searching for this error message shows a astonishing amount of questions about this, so you are in good company.
Some solutions tell you to disable automatic web proxy detection, or disconnect the network cable from the server during the installation of the DHCP role.
When you wish to know what happens, then look in the %SYSTEMROOT%\System32\DHCP for some logfiles.
In our case the newly installing dhcp server detects a already running dhcp server in the network and so refuses to install a local DHCP server.
So it's clear why disconnecting the network cable solves the installation problem, the other dhcp server is then no longer visible.
But why, why is preventing the installation of the dhcp server role?
And why, why is there such a cryptic nonsense error message instead of a real error message?