After password or remote registry changes to WinVNC you may want to restart 
the service.

Solution:

1) Create a batch file with the commands:

@echo off
Net stop winvnc
net start winvnc
"c:\program files\orl\winvnc" -servicehelper

Please note that the winvnc service name and path may be different under 
different VNC flavours (check your Services applet for more info).

2) Copy the batch file to the target workstation.

3) Use VNC and execute the batch file (this will drop your current session).
Alternatively use Xcmd or PsExec to run the file in a remote DOS window (NT, 
2000 and XP only).

Please note you should test this method before attempting it on a live system.