I have the same problem if i tried to open WMI Control propertie on a
remote control pc in Computer Management section Services and
Applications
Do you have SNMP installed on the hosts?
Start -> Help and Support, search on "install snmp".
There should be an article on how to install SNMP.
There are articles at Microsoft on WMI SNMP, like
http://msdn2.microsoft.com/en-us/library/aa393621(VS.85).aspx. WMI by
itself is just another interface to define hardware but I'm not sure
it supports anything to network or manage hosts across a network using
that interface; see
http://en.wikipedia.org/wiki/Windows_Management_Instrumentation. I've
never gotten into this level of enterprise management of hosts so you
might want to ask in a system admin or networking group. SNMP popped
into my head when you mentioned WMI and trying to use it across a
network.
I have never used SmartCode Manager (
https://www.s-code.com/) but I
have used standard VNC, UltraVNC, and TightVNC (don't know what
version they rolled into their product). They have their own FAQ.
One article was
https://www.s-code.com/products/vncmanag/faq.aspx#6
and maybe it applies to you. They also have forums there. Their site
is a bit crappy in that it mixes secure and non-secure content for no
good reason. A search on "rpc" turns up some articles there, like
having to punch through the firewall by allowing the ports for remote
admin. Although you said there is no firewall on your workstations,
Windows XP and onward come with one so maybe your users enabled it.