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After a Windows update I cannot connect to a Windows Server 2008 machine via RDP. As an alternative, I remotely installed UltraVNC using PsExec.

The WinVNC service starts successfully but when I try to connect remotely, I receive the following error message:

This server does not have a valid password enabled.
Until a password is set, incoming connections cannot be enabled.

Since I don't have desktop access to the machine, how do I set the password?

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3 Answers 3

You can remotely set the registry key

[HKEY_LOCAL_MACHINE\SOFTWARE\RealVNC\WinVNC4] "Password"=hex:xx xx xx xx

to figure out what hex value to set you can set it on a test machine and copy the resultant value, or you could use a tool which there a many of to generate one for you


it even looks like there is an app for this I havent tested this I have only just searched for it on google, but there are a load of results with similar promises

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Does the encrypted password key vary by machine? – pate Apr 10 '10 at 18:38
The password key is a base64 encoding of whatever password you choose. – Charles Gargent Apr 19 '10 at 7:05

Starting from UltraVNC 1.0.5 saves password information into file file %programfiles%\ultravnc\ultravnc.ini


1) you can to understand how uvnc generates password 2) You can install vnc on you computer and copy passwd from local installed ini file, and past it into ultravnc.ini on remote host. 3) You can use Windows Authentification, and connect with windows creditionals.

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it seems that with version 1.0.9 , ultravnc does not like someone to tamper with ultravnc.ini password , giving the message " this server does have a valid password" after restarting the service. A workaround is to switch to registry mode : UseRegistry=1 in ultravnc.ini – Max Oct 22 at 9:23

I was looking for a way to change my users teamviewer passwords without having to log in or talk them through it (from a security and side too). For those having issues with remote VNC passwords, have you tried intelliadmin network administrator 3.0? You can remote enable/disable RDP/ CD ROMS/ USB and change VNC passwords provided you have the credentials of the deice you are connecting to.

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Are you affiliated with IntelliAdmin? – Deer Hunter Nov 4 at 15:07

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