> The message is Error code 335544721 Unable to complete network
> request to host xxxxxx. Failed to establish a connection. No
> connection could be made because the target machine actively refused
> it.
>
> I copied a program update to a number of users on a particular site,
> and in all cases except, for one PC where this error message
> appeared, the update worked. All of these PC's connect to the same
> server. The update has also been installed on three other sites, with
> no problems. The FB database on the server is obviously working, as
> the other PC's were able to connect and the firewall on the server
> was obviously allowing the connection. Now comes the peculiar part.
> If, on the PC that is causing the problem, I re-install the old
> version of the program, the error message does not appear and the
> program works normally. I have re-installed the FB client on this PC,
> checked the services file and windows firewall, and tried connecting
> with the firewall turned off. In all cases, the original version of
> the program connects, whilst the updated version produces the error
> message. I have also tried connecting to a database on another server
> to which this site has access, with the same results. This particular
> PC is an older, slower PC with windows XP home SP2, whereas the other
> PC are all newer with either XP professional SP2 or Vista. Other than
> this, the setup is identical on all of the PC's. Can anybody help
> please?
>

XP home certainly sounds the odd man out here.
Wasn't it first released without a proper TCP stack of something?
It was also very difficult in the first instance to manage it's internal
firewall protection setup. Sounds to me like an internal blocking.
Alan