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?

4 Answers 4


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

  • Does the encrypted password key vary by machine? Apr 10, 2010 at 18:38
  • The password key is a base64 encoding of whatever password you choose. Apr 19, 2010 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.

  • 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, 2015 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.

  • 4
    Are you affiliated with IntelliAdmin? Nov 4, 2015 at 15:07

You should run all those command with PSSEXEC

  1. Get the PID of the process with tasklist | findstr winvnc
  2. Kill the process with taskkill /pid X (X should be the PID number of the process winvnc.exe service you got in step 1).
  3. Create a new ultravnc.ini file on the installation directory of WinVNC on the server. You can setup a UltraVNC service on your computer first and copy the password on the passwd field of the ultravnc.ini file in your local installation. The basic file has only 3 lines. We will add each line with one echo:
echo [ultravnc] > "c:\program files\bbva\ultravnc\ultravnc.ini"
echo passwd=999999999999999999 >> "c:\program files\bbva\ultravnc\ultravnc.ini"
echo passwd2=888888888888888888 >> "c:\program files\bbva\ultravnc\ultravnc.ini"
  1. Start the WinVNC service with net start uvnc_service

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