Categories: Windows 11 & Windows 10Windows Server

SOLVED: UltraVNC Can’t Send CONTROL ALT DEL on Windows 7 64bit or Server 2008 R2 and Screen Refresh Issues

UPDATE: Note that I have given up on UltraVNC and gone to RealVNC because it supports 4 monitors (and I find TightVNC just too slow when the screens are busy).  Pay the $30 for the Personal version and save the time.

BACKGROUND:

Sooo, I needed a fast VNC that would support multiple monitors so I can run some digital signage and digital artwork remotely on Win 7 64 Bit.  Previously I had used the standard REALVNC but it has problems with running as a service in 64bit PC’s, which I had previously tollerated on my Windows Vista implementations.  It’s been a few years and so I took another crack at it and found that the current build of UltraVNC:

  • supports multiple monitors
  • supports Windows 7 and Server 2008 R2
  • supports 64 bit
  • supports Active Directory tie in

NO CONTROL+ALT+DEL:

What it can’t seem to do is consistantly get past the Windows Login/Logon screen.  From several blogs, the cause is apparently that UAC has to be ENABLED, which in my case is not a problem, because I always leave UAC on under Windows 7.  CTRL ALT DEL usually has no apparent response from the host PC.  After playing with settings and reading blogs I found three suggested work arounds, two of which was a good one:

  1. Disable the CONTROL ALT DEL (C A D) requirement via the registry (this is a VERY bad idea in corporate environments that should get you fired).
    .
  2. Click the blue wheel (Ease of Access) icon in the bottom left corner of the screen and select TYPE WITHOUT THE KEYBOARD – ON SCREEN KEYBOARD.  The problem with this option was that the screen would not refresh automatically… which is annoying.   See REFRESH SOLUTION below.
    .
  3. I also found that putting the ultraVNC client into FULL SCREEN sometimes let me use the SEND CONTROL+ALT+DEL key

NO SCREEN REFRESH:

From  http://www.appdeploy.com/messageboards/tm.asp?m=76509 I found the solution was to change the following settings in C:\PROGRAM FILES\ULTRAVNC\UltraVNC.INI

[poll]
TurboMode=1
PollUnderCursor=0
PollForeground=1
PollFullScreen=1
OnlyPollConsole=0
OnlyPollOnEvent=0
EnableDriver=1
EnableHook=1
EnableVirtual=0
SingleWindow=0
SingleWindowName=

View Comments

  • Nick Harvey's solution is easy to re-create:
    1. Logon to the Administrator account on the remote PC locally to get to the desktop.
    2. Send remote Crtl-Alt-Del command via UltraVNC from a client PC. [You will see a pop-up message that asks if you want to “Make change to UAC registry to allow CAD”.]
    3. Click "Yes" to allow changes to the registry to allow CAD.
    4. Click "Continue" when the next UAC pop-up appears.
    You're done! You can now send the CAD remotely from the UltraVNC client to your Windows 7 Pro PC.

  • From spiceworks

    VNCScan works best for this but you can do it manually, also.

    1) "Start menu" -> "Execute" - > gpedit.msc
    2) Navigate to "Computer Configuration" -> "Administrative Templates" -> "Windows Components" -> "Windows Logon Options"
    3) Double-click on the "Disable or enable software Secure Attention Sequence" parameter.
    4) Check "Enable", then select "Services" in the combobox.
    5) Apply the modification

    Worked great for me

  • I found that turning on Remote Desktop on Windows 7 systems and Windows 2008 servers allowed UltraVNC (tested with severial versions of it) corrected the Crtl+ALT+Del and other problems. Still researching why...

    • Not sure if this is related or not, but I was doing something that caused UltraVNC to prompt me "Make change to UAC registry to allow cad" (not sure what CAD is) and I clicked yes, now it works. ???

  • Guys,

    I am not sure what the problem is, but inspite of the above changes being made, I was not able to proceed. Any help on this will be greatly appreciated. Thanks

    • Good Day. This did resolve my issue, but I will leave your post for others to comment on; perhaps others have alternate solutions.

      Thanks for visiting our site.

  • This helped me out also I used the full screen and the on screen keyboard + real keyboard combo and it got me passed the initial logon screen on windows 2008r2

    Thanks for this trick

  • Good thinking, Ian.
    I couldn't get onto a couple of win7 machines, but your idea of using the onscreen keyboard worked a treat. I just hold down ctrl + alt (on my keyboard) and clicked 'del' with the mouse.

    This should get my by until Uvnc devs work something out.

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Published by
Ian Matthews
Tags: 64 bitc a dcadcontrol alt deletedeldisable aerofailsrealvncscreen refreshtightvncultraVNCultravnc.inivncwindows 7Windows Server 2008 R2
13 years ago

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