vSphere Client requires Windows XP SP2 or later. vSphere Client cannot be installed on a domain controller.

A couple of days ago I came across something quite annoying after one of my clients had their server putting the last foot into the grave. I converted the physical machine into a VM, arranged another host and moved it over in a hurry, all worked fine and then remotely I tried to install vSphere client on this old converted Windows 2003 Domain Controller so I could manage the host as the ipsec tunnel for some reason was not passing all traffic properly.

Anyway, I get this message during installation of vSphere client 5.5 "vSphere Client requires Windows XP SP2 or later.  vSphere Client cannot be installed on a domain controller." which was really annoying. I could not deploy another VM quickly enough as I had to do some work for this client right quick. Interesting enough the installation program of vSphere client has some switches you can use and browsing through the help I managed to find this one here:

/VSKIP_OS_CHECKS="1"

So, running the installation program with this switch basically make it ignore that the VM is a domain controller and the installation go through just fine. It is not recommended or supported by VMware by for me it was needed and I didn't have much of a choice, maybe the same situation you may get into the future especially when dealing with legacy systems (screw accounts software that is 8 years old)