VNC Viewer : Error "unable to connect to hotst: Connection refused (10061)"

[Ron McKenzie]

I get this error when I attempt to connect from my laptop to the
VNCserver 4.0 that I installed on my home PC.  I can connect if I use
v.3.3.3 R3 that is also installed on this laptop.  I was able to
connect once from this laptop using 4.0 (Monday night 11/15) and my
bro-in-law has no problem with 4.0 from his PCs, however, something
about my install here is "off".

All advice cheerfully accepted.  

Ron