If you start a VNC connection from your Viewer and get as far 
as getting to a VNC password prompt, you're 90-percent of the 
way there. Usually the problem at this point is simply not
entering the right password. Which sounds ridiculous...until
you consider that a Windows VNC Server may have *two* passwords
set on it! See this category for an explanation of that strange
situation: Changing a VNC password on a Windows PC