When you click on the VNC Viewer icon, it opens the Connection dialog box shown below.
There are a lot of options on the Viewer’s connection dialog box. I don’t touch any of them. All I have to do is to enter then name of the computer running VNC Server (in the case above, the name I assigned in Windows is htpc2), and then click the Connect button.
Once you click the Connect button, the Viewer will attempt to make contact with the Server on the other computer. If it’s successful, you’ll get a dialog box asking for the password. If not, you’ll get a failure notice.
Once you enter the password and its accepted, you’ll have remote administration capabilities to the other computer.
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