Strange screen saver problem

James [Wez] Weatherall jnw "at"
Tue, 03 Mar 1998 10:26:16 +0000

On Tue, 3 Mar 1998, Brian Knotts wrote:

> This occurs whenever the Windows NT host is in screen saver mode ("Logon
> Screen Saver") or when the logon screen is present. Only the normal
> desktop view succeeds in displaying in vncviewer.

It's a known limitation of WinVNC that it cannot handle non-user desktops.
Desktops are a mechanism used by Windows NT (not Windows 95 or 98) to
isolate tasks that need to be secure, such as the logon shell and
locking/unlocking of workstations.  Included in this is the screen-saver.
Unfortunately, this means that since WinVNC runs on the desktop of the
logged-in user, it can't access the logon or screen-saver desktops.  The
result is that you attempt to connect to the server and the connection
fails in the manner you describe.  To avoid this, WinVNC always tries to
close down the screen-saver if it is running, when a connection is made.

This is partly why it isn't currently possible to use WinVNC to
lock/unlock or logon/logoff NT boxes.

I hope that answers your question.


James "Wez" Weatherall
Olivetti & Oracle Research Laboratory, Cambridge, UK.
Tel : Work - 343000