There are a few other posts (e.g. Remotely set VNC service password ) on that subject but they are narrow to one specific VNC software/version.
I have a situation whereby I have about 500 PCs on a Windows Domain and they are setup with a mix of VNC versions - RealVNC4, UltraVNC, TightVNC, and each of different versions.
So some use an ini file (like most recent version of UltraVNC), some use Registry and they use different section of the registry.
Anyone knows of a script/tool that will just try all options and set the password?