<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="GENERATOR" content="Mozilla/4.51 [en] (X11; I; Linux 2.2.6 i686) [Netscape]">
<meta name="keywords" content="VNC, AT&T Laboratories Cambridge, Virtual Network Computing, thin-client">
<title>WinVNC - The Win32 VNC server</title>
<link REL="stylesheet" HREF="styles.css" TYPE="text/css">
<style>
<!--
.itemheader { font-family: Arial, sans-serif; color: rgb(128,0,128); font-weight: bold; font-size: smaller }
-->
</style>
</head>
<body bgcolor="#FFFFFF" vlink="#000080" marginheight="0" topmargin="0" leftmargin="0" marginwidth="0">
<TABLE BORDER=0 CELLSPACING=0 CELLPADDING=0 WIDTH="100%" >
<tr>
<td ALIGN=CENTER VALIGN=TOP WIDTH="125" BGCOLOR="#EECC80">
<center><a href="index.html"><img SRC="sidelogo.gif" ALT="VNC logo" BORDER=0 height=113 width=120></a></center>
</td>
<td VALIGN=TOP WIDTH="20"><img SRC="spacer.gif" HSPACE=8 height=1 width=1></td>
<td>
<table BORDER=0 WIDTH="100%" >
<tr>
<td WIDTH="90%" valign="center">
<center>
<h1>
<IMG SRC="vnctitle.gif" WIDTH=370 HEIGHT=30 ALT="Virtual Network Computing"></h1></center>
</td>
<td WIDTH="10%"><a href="http://www.uk.research.att.com/"><img SRC="attlogo.gif" ALT="AT&T" BORDER=0 height=75 width=66 align=RIGHT></a></td>
</tr>
</table>
</td>
<td WIDTH="5%"></td>
</tr>
<tr><td colspan=5 bgcolor="#eecc80"><img src="spacer.gif" height=3 vspace=0 hspace=1></td></tr>
<tr><td bgcolor="#eecc80"><img src="spacer.gif" height=4 vspace=0 hspace=1></td><td colspan=4></td></tr>
<tr>
<td ALIGN=CENTER VALIGN=TOP WIDTH="125" BGCOLOR="#EECC80">
<center><table BORDER=0 CELLSPACING=0 CELLPADDING=0 WIDTH="100%" >
<tr>
<td><a href="index.html"><img SRC="homebutton.gif" ALT="[Home]" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="screenshots.html"><img SRC="screenbutton.gif" ALT="[screenshots]" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="start.html"><img SRC="startbutton.gif" ALT="[getting started]" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="docs.html"><img SRC="docbutton.gif" ALT="[documentation]" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="faq.html"><img SRC="faqbutton.gif" ALT="FAQs" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="download.html"><img SRC="downloadbutton.gif" ALT="[download]" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="intouch.html"><img SRC="intouchbutton.gif" ALT="[keep in touch]" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="contribs.html"><img SRC="contribbutton.gif" ALT="Others' ports and add-ons etc" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="help.html"><img SRC="helpbutton.gif" ALT="Project ideas" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="vncpeople.html"><img SRC="vncpeoplebutton.gif" ALT="VNC people" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="http://www.uk.research.att.com/search.html"><img SRC="searchbutton.gif" ALT="Search" BORDER=0 height=33 width=120></a></td>
</tr>
<tr>
<td><a href="http://www.uk.research.att.com/"><img SRC="attbutton.gif" ALT="[AT&T Laboratories Cambridge]" BORDER=0 height=33 width=120></a></td>
</tr>
</table></center>
</td>
<td VALIGN=TOP WIDTH="8%">
<center><a href="docs.html"><img SRC="backbutton.gif" ALT="back to docs" HSPACE=2 BORDER=0 height=20 width=20></a></center>
</td>
<td VALIGN=TOP WIDTH="100%">
<h2>
<b>WinVNC - The Windows NT VNC server</b></h2>
<img SRC="winvnctray.GIF" ALT="WinVNC in system tray" HSPACE=6 VSPACE=5 height=118 width=199 align=RIGHT>WinVNC
is a VNC server that will allow you to view your Windows desktop from any
VNC viewer. Because Windows in its present, standard incarnation, only
supports a single graphical user being logged in at any one time, WinVNC
makes the existing desktop of the PC available remotely, rather than creating
a separate desktop as happens with the Unix server. It is only fair to
emphasise this: VNC does <b><i>not</i></b> make an NT machine into a multi-user
server in the same way that Citrix-based software, for example, does. A
single NT machine can therefore be accessed by multiple users, but if they
all connect at the same time they will all see the same desktop!
<p>On the other hand, WinVNC will run on Windows 95, Windows98, Windows
NT 4.0, Windows 2000 and on any future Win32-based systems, without the
need to replace any system files or run any OS-specific versions of the
program. It is a standard application that can be run from the Start...
menu and closed down just as easily.
<p>WinVNC can also be run as a service, which means that you can log
in remotely, do some work, and log out again. We recommend that you
run it in this mode. See below for more details.</p>
<p>And, of course, WinVNC is free. We hope that making the source code
available will enable programmers who know more about the internals of
Windows than we do to suggest improvements to any and all aspects of WinVNC.
<p>If you haven't yet read the '<a href="start.html">Getting Started</a>'
page, you might like to do that first to give you the general concepts.
<h3>
Installation</h3>
WinVNC is fairly simple to install and even easier to use:
<ul type="disc">
<li>
Run the WinVNC setup program.</li>
</ul>
<ul type="disc">
<li>
Install the default VNCHooks registry settings by selecting
Install Default Registry Settings from the WinVNC folder in the Start menu.
This will install the default hooks settings, which are tweaked to cope
with some common, uncooperative applications, such as the clock. See later
for more information about the registry settings. </li>
</ul>
<ul type="disc">
<li>
WinVNC can now be run from the Start menu. Alternatively, you can use the
Start->Settings->Taskbar menu to add a shortcut to your Startup group,
which will cause WinVNC to be run every time you log in.</li>
</ul>
After some initial tests, we suggest you run WinVNC as a service. See
below for more information.
<h3>Using WinVNC</h3>
On starting, WinVNC will add a small, green version of the VNC icon to
the system task bar. Clicking on this icon with the right mouse button
will cause a menu to be displayed, with the following options on it:
<ul>
<li>
<span class="itemheader"><b>Properties</span></b> - This will cause the
Properties dialog to be displayed, allowing the user to change various
WinVNC parameters. </li>
<li>
<span class="itemheader"><b>Kill All Clients</span></b> - This will disconnect
all currently connected clients from the server. </li>
<li>
<span class="itemheader"><b>Close</span></b> - Shutdown the server. </li>
</ul>
Moving the mouse over the icon should cause the IP addresses of the local
machine to be displayed, if they can be discovered at that time.
<p>You can connect to the server from another machine using a VNC viewer,
as described in the <a href="start.html">Getting Started</a> page.
<h3>WinVNC Properties</h3>
The following options are available from the Properties dialog.
<p><font color="#800080">Incoming Connections</font>
<ul type="disc">
<li>
<span class="itemheader">Accept Socket Connections</span> - The server
normally accepts direct, socket-based connections from the vncviewer program.
Clearing this tick-box disables direct connection to WinVNC, so that only
the CORBA interface used by our internal version may be used to start a
connection. (See <a href="internalversion.html">AT&T internal version</a>
info). For the public version, clearing this will disable any incoming
connections.</li>
<li>
<span class="itemheader">Display Number</span> - This allows the user to
specify the display number which the server will use. There is normally
no need to change this from the default of zero.</li>
<li>
<b><font color="#800080">Auto</font></b> - This tick box indicates to WinVNC
whether it should use the display number specified in the Display Number
box, or whether it should use the first display number not already in use
on the server machine.</li>
<li>
<span class="itemheader">Password</span> - Incoming connections must be
authenticated to verify that the person connecting is allowed to connect
to this machine. This text box allows your password to be specified for
authentication.</li>
<li>
<span class="itemheader">Disable Remote Keyboard & Pointer</span> -
Any new incoming connections will be able to view the screen but not send
any input.</li>
</ul>
<font color="#800080">Update Handling</font>
<p><i>Note that clicking in a window will generally cause it to be updated,
so if you have certain applications which don't update very well, try this!
The default update handling settings should be the right ones for most
people, and in general you will slow things down by changing them, so don't
do this unless you have applications which cause problems.</i>
<ul type="disc">
<li>
<span class="itemheader">Poll Full Screen</span>- Some applications are
incompatible with the methods currently used in WinVNC to trap screen updates.
For this reason, it is sometimes useful to be able to poll the entire screen
in order to check for changes, sacrificing performance for accuracy. </li>
<li>
<span class="itemheader">Poll Foreground Window</span> - Polling only the
currently selected window for changes is less CPU intensive than full-screen
polling and often gives similar results, for example when using the Command
Prompt, which is not normally compatible with WinVNC. </li>
<li>
<span class="itemheader">Poll Window Under Cursor</span>- A variation on
Poll Foreground Window, this option causes the window under the mouse cursor
to be polled for changes. Both options may be enabled simultaneously if
required. </li>
<li>
<span class="itemheader">Poll Console Windows Only</span>- When this option
is set, the only windows which will be ever be polled are Command Prompts.
This works well in conjunction with Poll Window Under Cursor, to use polling
only when the cursor is over a console window. </li>
<li>
<span class="itemheader">Poll On Event Received Only</span>- When this
option is set, the screen will only be polled for updates when a mouse
or keyboard event is received from the remote client. This is provided
for low bandwidth networks, where it may be useful to control how often
the screen is polled and changes sent. </li>
</ul>
The user's settings are saved into the user-specific section of the registry
when WinVNC quits, meaning that they will be used next time you run WinVNC.
<br>
<ul type="disc"> </ul>
<h2>
Running WinVNC as a service</h2>
WinVNC can now be made to run as a service process under both Windows NT
and Windows 95/98, by following the instructions outlined below.
On NT, you can also then send Ctrl-Alt-Del to the server, allowing you to unlock a locked workstation, for example.
The following 'features' should also be pointed out:
<p>Windows NT 'features':
<ul>
<li>
There will be one password for the machine, rather than one per user.</li>
<li>
The system tray icon is not always correctly displayed, so you won't always
be able to tell whether someone else is connected except by the fact that
things work more slowly.</li>
</ul>
Windows 95 'features':
<ul>
<li>
Whether or not the VNC password is set per-machine or per-user depends
on the settings in the Passwords section of the Control Panel. If
Win95 is set to use a different set of registry values for each user then
when a user logs in, the password will change from the per-machine VNC
password to that user's VNC password. If Win95 is set to use the
same settings for all users then the per-machine VNC password will always
be used.</li>
</ul>
General features for both Windows NT and Windows 95:
<ul>
<li>
Anything which causes the Windows VNC server to change screen resolution
will also cause all viewers to be disconnected, and you'll need to reconnect.</li>
<li>
When WinVNC is running as a system service, no user-level copies can be
run at the same time. </li>
</ul>
Here's how to get it running as a service, assuming you've already installed
it.
<ol>
<li>
<b>Wnindows NT </b>: You need to have administrator privileges on the local
machine, so log on as administrator if your account doesn't have these.</li>
<li>
Open a Command Prompt and <tt>cd</tt> into the directory into which you
installed WinVNC. eg:</li>
<p><br><tt>D:\> C: </tt>
<br><tt>C:\> cd "\Program Files\ORL\VNC" </tt>
<li>
Install the WinVNC service using the -install option. A dialog box will
appear to indicate the success or failure of the operation.</li>
<p><br><tt>C:\Program Files\ORL\VNC> winvnc -install</tt>
<p><b>Windows 95 :</b> The WinVNC service is now running and is installed
to run whenever the system boots up into Windows 95.
<p><b>Windows NT </b>: The WinVNC service is installed and set up to run
whenever the machine is booted into Windows NT but <i>IS NOT YET RUNNING</i>!
You can run and stop the WinVNC service using the Windows control panel,
or using "net start" and "net stop"
<p><tt>C:\> net start winvnc</tt>
<li>
If you wish to change the WinVNC settings (eg. password) when it is running
as a service and is therefore not visible on the taskbar, you must
use the -settings option. </li>
<br>Open a command prompt and move into the directory into which you installed
WinVNC, as described in part 2) above. Use the -settings option to
cause the service to display its Properties dialog.
<p><tt>C:\Program Files\ORL\VNC> winvnc -settings</tt>
<p><b>NOTE : Windows NT </b>: The settings used by the winvnc service are
the Default user settings and are stored per-machine, rather than on a
per-user basis as is done when running WinVNC normally. Access for all
users will be controlled by the one machine-specific password.
<p><b>NOTE : Windows 95 </b>: If Win95 has been set to use different settings
for each user then the settings used are those of the currently logged
in user. If no user is logged in or Win95 is set to use the same
settings for all users then the settings used are the Default user settings
and are stored per-machine, rather than on a per-user basis as is done
when running WinVNC normally. (Under Win95, pressing Cancel on the
login dialog gives access to the Default user settings.)
<li>
When you wish to install a new version of WinVNC or simply wish to remove
WinVNC from your machine, you must first remove the service
from the system, using the -remove option.</li>
<br> Open a command prompt and move into the directory into which
you installed WinVNC.
<br> Use the -remove option, which will automatically stop the service
and then remove it, and show a dialog box to indicate the success or failure
of the operation.
<p><tt>C:\Program Files\ORL\VNC> winvnc -remove</tt>
<p>NOTE : Failure to remove the service usually indicates that it was not
installed in the first place!
<li>
The full command-line options available are as follows (for version R19
and later). You probably won't need anything other than those listed above
unless you're a real VNC power-user!</li>
<p><br><tt>-run </tt>Causes WinVNC to run
normally & ignore rest of command-line.
<br><tt>-install </tt>Installs the WinVNC service and continues reading
the command-line.
<br><tt>-remove </tt>Removes the WinVNC service and continues
reading the command-line.
<br><tt>-settings </tt>Tells a running copy of WinVNC to show its Properties
box.
<br><tt>-kill </tt>Kills a running copy of WinVNC.
<br><tt>-about </tt>Tells a running copy of WinVNC to
show its About box.
<p>If no options are given then WinVNC runs normally. Multiple option may
be given, so, for example, to upgrade from a running copy of WinVNC to
a new one, you could use:
<br><tt>WinVNC_new -remove -install</tt>
<br>which will stop & remove the old copy & install the new one
as a service, or
<br><tt>WinVNC_new -kill -run</tt>
<br>which will stop the running copy & run the new version normally.</ol>
<h2>
WinVNC - Advanced Settings</h2>
Extra options have been added to WinVNC for use primarily by system administrators,
to tailor the server's behaviour to meet their particular needs.
The options are DWORD values which can be set in the system registry, and
tools such as the Windows Policy Editor can be used to apply these settings
across a large number of machines.
<p>Versions 3.3.2 R5 and later use a more sophisticated organisation of
these options to allow more flexibility. It also makes it rather
complex, so we're thinking about alternative ways of doing this. WinVNC
will currently look for settings in the following places:
<ol>
<li>
<b>Local machine-specific settings</b>. Options specified here are not
overridable. Location:</li>
<br>HKEY_LOCAL_MACHINE\Software\ORL\WinVNC3\
<li>
<b>Local default user settings. </b>Location:</li>
<br>HKEY_LOCAL_MACHINE\Software\ORL\WinVNC3\Default
<li>
<b>Local per-user settings</b>. These override the local default
user settings. If there is no current user, the username SYSTEM will be
used. Location:</li>
<br>HKEY_LOCAL_MACHINE\Software\ORL\WinVNC3\<i><username></i>
<li>
<b>Global per-user settings.</b> These are only read if AllowProperties
has not been set to zero (see below) Location:</li>
<br>HKEY_CURRENT_USER\Software\ORL\WinVNC3</ol>
Most options can only be specified in a subset of these places, as specified
in each option's description below.
<h3>
Advanced Options:</h3>
<ul><b><font color="#800080">AuthRequired</font></b>
<br>By default, all WinVNC servers will not accept incoming connections
unless the server has had its password field set to a non-null value.
This restriction was placed to ensure that misconfigured servers would
not open security loopholes without the user realising. If a server
is only to be used on a secure LAN, however, it may be desirable to forego
such checking and allow machines to have a null password. Setting
this registry value to zero will disable null-password checking by WinVNC.
<b>Local
machine-specific setting.</b>
<p><b><font color="#800080">AllowLoopback</font></b>
<br>By default, WinVNC servers disallow any vncviewer connections from
the same machine. For testing purposes, or, potentially, when
using multiple instances of WinVNC on Windows Terminal Server, this behaviour
is undesirable. Setting this registry entry to 1 will cause local-loopback
connections to be allowed. Setting it to zero will filter out such
connections. <b>Local machine-specific setting.</b>
<p><b><font color="#800080">AllowProperties</font></b>
<br>If this is set to zero, the user is not allowed to view the properties
dialog and hence cannot change any settings, including the password.
Note that this stops all global per-user settings. A valid password must
therefore be in force before using this setting, generally in the local
default-user setting.<b> Local per-user setting.</b>
<p><b><font color="#800080">AllowShutdown</font></b>
<br>If this is set to zero, the user is not allowed to close down WinVNC.
<b>Local
per-user setting.</b>
<p><b><font color="#800080">AutoPortSelect</font></b>
<br>Causes WinVNC to select the first available display number automatically.
Corresponds to the 'Auto' checkbox in the Properties dialog. <b>Local or
Global per-user setting</b>
<p><b><font color="#800080">CORBAConnect</font></b>
<br>Only relevant in internal AT&T version. <b>Local or Global per-user
setting</b>
<p><b><font color="#800080">DebugLevel</font></b>
<br><b><font color="#800080">DebugMode</font></b>
<br>Run-time logging of all internal debug messages is now supported. Log
data may be output to a file or a console window (or the MSVC debugger
if the program was compiled with debugging active.) Two registry
keys are used:
<p><i>DebugMode</i> indicates which logging methods to use,
<br>[1 = MSVC debugger]
<br>2 = Output to log file Winvnc.log in the WinVNC directory
<br>4 = Output to a console window, displayed on-screen
<br>Any combination of the above values may be used. e.g. DebugMode=6
will cause output to be sent both to the WinVNC.log file and to the a console
window on the desktop.
<p><i>DebugLevel</i> indicates how much debug information to present. Any
positive integer is valid. Zero indicates that no debugging information
should be produced and is the default. A value of around 10-12 will
cause full debugging output to be produced. <b>Local machine-specific setting.</b>
<p><b><font color="#800080">ConnectPriority</font></b>
<br>By default, all WinVNC servers will disconnect any existing connections
when an incoming, non-shared connection is authenticated. This behaviour
is undesirable when the server machine is being used as a shared workstation
by several users or when remoting a single display to multiple clients
for vewing, as in a classroom situation.
<p><i>ConnectPriority</i> indicates what WinVNC should do when a non-shared
connection is received:
<br>0 = Disconnect all existing connections.
<br>1 = Don't disconnect any existing connections.
<br>2 = Refuse the new connection.
<p>This is a <b>Local machine-specific setting.</b>
<p><b><font color="#800080">InputsEnabled</font></b>
<br>Corresponds (inversely) to the 'Disable Remote keyboard and pointer'
option in the Properties dialog box. <b>Local or Global per-user setting</b>
<p><b><font color="#800080">LockSetting</font></b>
<br>WinVNC can be made to take actions when a viewer disconnectsby setting
this value as follows:
<br>0 - none
<br>1 - lock workstation on disconnect (not currently implemented)
<br>2 - logoff on disconnect
<br><b>Local or Global per-user setting</b>
<p><b><font color="#800080">Password</font></b>
<br><b>Local or Global per-user setting</b>
<p><b><font color="#800080">PollUnderCursor, PollForeground, PollFullScreen,
OnlyPollConsole, OnlyPollOnEvent</font></b>
<br>These correspond to the options in the Properties dialog box.<b> Local
or Global per-user settings</b>
<p><b><font color="#800080">PortNumber</font></b>
<br>specifies the port number to be used for VNC. You will need to disable AutoPortSelect to use this.
<br><b>Local or Global per-user setting</b>
<p><b><font color="#800080">SocketConnect</font></b>
<br>This corresponds to the 'Accept Socket Connections' option in the properties
dialog box and is a <b>Local or Global per-user setting</b>.</ul>
<h2>
VNCHooks - Advanced Settings</h2>
WinVNC uses a special library, VNCHooks, to hook into the other running
applications and retrieve notifications of areas of the screen being changed.
The VNCHooks library uses the messages sent to visible Windows to decide
which areas need considering for update. Not all applications use the same
method of updating the screen, so you can tweak the method used by WinVNC
for particular applications by editing the registry. All the entries listed
can be found under
<center>
<p>HKEY_CURRENT_USER\Software\ORL\VNCHooks\Application_Prefs</center>
<ul type="disc">
<li>
<span class="itemheader">use_GetUpdateRect</span></li>
<br>When a window recieves a message, (WM_PAINT), indicating that it should
repaint itself, it is possible to find out precisely which regions have
changed, so that WinVNC need only scan those for potential updates,increasing
efficiency. However, this can cause graphical glitches occasionally, particularly
when an application scrolls the contents of its window, in which case only
the revealed section of the window is marked as needing to be updated.
If these glitches prove to be a problem then edit the <tt><i><appname></i>\use_GetUpdateRect</tt>
entry in the registry. A value of one indicates that this optimisation
will be used, while a value of zero indicates that it will not. </ul>
<ul type="disc">
<li>
<span class="itemheader">use_Timer</span></li>
<br>A number of Windows applications, most notably the Clock program, use
WM_TIMER events to trigger updates to their displays, rather than WM_PAINT
messages. By default, timer messages are not used to notify WinVNC of potential
updates, since many programs use timer events for purposes other than updating
the screen. As a result, the clock and a few other applications don't normally
update correctly under WinVNC. The fix to this is to edit the <tt><i><appname></i>\use_Timer</tt>
entry in the registry. A value of one indicates that WM_TIMER messages
will trigger WinVNC updates, while a value of zero indicates that they
will not. </ul>
<ul type="disc">
<li>
<span class="itemheader">use_KeyPress</span></li>
<br>Some Windows applications write characters directly to the screen when
a user types into a window, rather than using WM_PAINT messages to cause
the text to be redrawn. To fix this, WinVNC can scan the window every time
a key is pressed, in order to catch the change. To set this value for a
problem application, edit the <tt><i><appname></i>\use_KeyPress</tt>
entry in the registry. A value of one indicates that key presses will cause
updates, while a value of zero indicates that they will not. </ul>
<ul type="disc">
<li>
<span class="itemheader">use_LButtonUp, use_MButtonUp</span>, <span class="itemheader">use_RButtonUp</span>,</li>
<br>Some Windows applications update the display directly in response to
mouse clicks, without using intermediate WM_PAINT messages, for example.
In order to catch such updates, it is necessary to trigger WinVNC to update
the relevant window whenever the left mouse button is released. To set
this value for a problem application, edit the <tt><i><appname></i>\use_LButtonUp</tt>
entry in the registry. A value of one indicates that left-button clicks
will cause updates, while a value of zero indicates that they will not.
The same rules apply to the middle and right buttons using the appropriate
value name.</ul>
<ul type="disc">
<li>
<span class="itemheader">use_Deferral</span></li>
<br>The VNCHooks library catches messages sent to windows <i>before</i>
they are dealt with by the window. As a result, sending an update message
to WinVNC to indicate the potential change can result in WinVNC sending
the updated area to the client before it has actually been redrawn by the
application! This is a common problem, especially on multiprocessor versions
of NT, so deferred updates are used by default. Deferred updates are handled
by posting a custom message back into the window's own message queue rather
than posting to WinVNC directly. By the time this custom message is seen
again by the VNCHooks library, the message that caused it will have been
handled and the update can then be forwarded to WinVNC without danger of
being handled prematurely. A few programs don't handle these extra messages
in their queue very well, so this optimisation is optional. It can be set
by editing the <tt><i><appname></i>\use_Deferral </tt>entry in the registry.
A value of one indicates that deferred updates will be used, while a value
of zero indicates that they will not. </ul>
<h2>
Running on other Win32 systems</h2>
WinVNC runs fine on NT3.51 but the absence of a system tray means that
the Properties dialog cannot be accessed. In addition, Ctrl-Alt-Del
from clients cannot be correctly interpreted under NT 3.51, limiting WinVNC's
usefulness when run as a service on this platform. It also runs on
NT5 beta. If you have a choice we recommend NT4.0 with the latest service
packs installed.
<br>
<h2>
Problems?</h2>
If you have difficulties which are not covered by this document, try reading
the <a href="faq.html">FAQ</a>. If that doesn't help then try the
<a href="intouch.html">mailing list</a>.
<br>If you try to contact the developers directly, please remember that
VNC has hundreds of thousands of users, and we cannot, in general, respond
to individual queries. We will read your message, but don't expect an answer!
<br>
<br>
<div align=right><a href="docs.html"><img SRC="backbutton.gif" ALT="back to docs" HSPACE=5 BORDER=0 height=20 width=20></a><i>go
back to <a href="docs.html">documentation</a></i></div>
</td>
<td WIDTH="5%"></td>
</tr>
<tr>
<td bgcolor="#eecc80"> </td><td ALIGN=CENTER VALIGN=TOP COLSPAN="4" WIDTH="100%">
<!-- Ruler here? -->
<center>
<p><i><font size=-1>For comments, feedback, etc, please see the '<a href="intouch.html">Keeping
in touch</a>' page</font>.</i>
<br><i><font size=-1>Copyright 1999 - AT&T Laboratories Cambridge</font></i></center>
</td>
</tr>
</table>
</body>
</html>
