Here’s how to install and start up an UltraVNC server from within an RDP session. This has been tested with UltraVNC 1.0.8 and a remote desktop session into a Windows XP Professional SP3 installation, but should work in other Windows / UltraVNC combinations as well.
- RDP into the target system, and install UltraVNC. Be sure to select the checkboxes for registering VNC as a service, and starting up the service at boot time.
- Set a VNC password for the currently logged in user by starting up the VNC server (Start > All Programs > UltraVNC > UltraVNC Server > Start UltraVNC Service), then entering a password when prompted
- Open up Regedit (Start > Run > regedit)
- Copy the HKEY_CURRENT_USER\Software\ORL\WinVNC3\Password entry’s current value
- Create a new binary value entry located at “HKEY_LOCAL_MACHINE\SOFTWARE\ORL\WinVNC3\Default\Password”. Paste in the value you copied in the previous step to this new entry’s value
- Reboot
That’s it! It may be possible to get VNC going without the reboot, but this is the combination that got a working installation going for me.