JVNC Administrator Guide

Installation, upgrading, removal, unattended deployment, and where everything lives.

1. Requirements

Windows 10 (1809+) or Windows 11, 64-bit.
No .NET installation is required: the installer ships a self-contained runtime.
Administrator rights to install to Program Files and to create the firewall rule.
Network: the server's TCP port (default 5900) must be reachable from the client.

2. Installing with `JVNC_<version>.exe`

Run the installer. Approve the elevation prompt.
Choose the components and options:
Install folder (default C:\Program Files\JVNC).
JVNC Server and/or JVNC Client — install only what the machine needs.
Desktop shortcuts, Start Menu shortcuts.
Start JVNC Server when I sign in — adds a per-user Run entry; the server then starts minimised in the tray and is listening within seconds of logon.
Windows Firewall rule for the server (inbound TCP, program-based, Private + Domain profiles). The rule is named JVNC Server.
Click Install. The installer copies the files, writes the shortcuts, registers JVNC in Apps & features, and optionally launches the server.

The manuals are installed to <install folder>\docs and linked from the Start Menu.

2.1 Unattended (silent) install

JVNC_1.0.1.exe /S [/D=C:\Path\To\JVNC] [/noserver] [/noclient] [/nostartup] [/nofirewall] [/nodesktop]

/S — silent; no UI, exit code 0 on success.
/D= — install folder (must be the last argument if the path contains spaces, quote it).
/noserver, /noclient — skip a component.
/nostartup — do not add the sign-in autostart.
/nofirewall — do not create the firewall rule.
/nodesktop — no desktop shortcuts.

The installer needs elevation even when silent; run it from an elevated prompt or a deployment tool that runs as SYSTEM/administrator.

3. Upgrading

Run the new installer over the existing installation. Stable releases are named JVNC_<version>.exe; pre-release builds are JVNC_Development_Build_<version>.exe and install/upgrade the same way. It stops running JVNC processes, replaces the files, and keeps all settings, certificates and logs (they live in each user's %APPDATA%\JVNC, not in the install folder). Clients' pinned server fingerprints remain valid because the server certificate is preserved.

4. Uninstalling

Settings → Apps → JVNC → Uninstall, or run <install folder>\Uninstall.exe (Uninstall.exe /S for silent). This removes the program files, shortcuts, autostart entry, firewall rule and the Apps & features entry.

Per-user data in %APPDATA%\JVNC (settings, logs, certificates and the TOTP secret) is kept by default so a reinstall picks up where it left off. The interactive uninstaller offers to delete it; silently, pass /purge to delete it for the current user.

5. Portable use (no installer)

Copy the Server and Client folders from the installer (or a build's JVNC package) anywhere and run the .exe files directly. The self-contained build has no prerequisites. Settings still go to %APPDATA%\JVNC. You must create your own firewall rule:

netsh advfirewall firewall add rule name="JVNC Server" dir=in action=allow program="C:\Path\Server\JVNC.Server.exe" enable=yes profile=private,domain

6. File and registry locations

Item	Location
Program files	`C:\Program Files\JVNC\Server`, `...\Client`, `...\docs`, `Uninstall.exe`
Per-user settings, logs, certificates	`%APPDATA%\JVNC\` (`server.json`, `client.json`, `*.log`, `server.pfx`, `client.pfx`)
Autostart (per user)	`HKCU\Software\Microsoft\Windows\CurrentVersion\Run\JVNC Server`
`jvnc://` URL handler (per user)	`HKCU\Software\Classes\jvnc` — registered by the client on first run
Uninstall entry	`HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall\JVNC`
Firewall rule	JVNC Server (inbound, program rule)
Start Menu	`%ProgramData%\Microsoft\Windows\Start Menu\Programs\JVNC\`

6.1 `server.json` reference

Key	Meaning
`Port`	Listening port.
`BindAddress`	Empty = all interfaces, or one local IP.
`AutoStart`	Start listening when the program starts.
`StartMinimized`	Start hidden in the tray.
`ConfirmIncoming`, `AutoSaveFolder`	File-transfer behaviour.
`Tls`, `RequireClientCert`, `AllowedClientThumbs`	Encryption and device certificates.
`RequirePassword`, `PasswordVerifier`	Connection password (default on); the verifier is `base64(salt):base64(PBKDF2)`. Empty verifier with `RequirePassword=true` triggers the set-password prompt at start.
`RequireTotp`, `TotpSecret`	One-time codes; the secret is stored as `dpapi:…` (encrypted for the user).
`IpAllowList`	Comma-separated IPs/CIDRs.
`DiffTolerance`	Change-detection noise tolerance per colour channel (default 8). Hides HDR/dithering flicker that would otherwise make the whole screen "change" every frame; 0 = exact comparison.
`DiffMinBytes`	Bytes per 64×64 tile that must exceed the tolerance before the tile counts as changed (default 12).
`ApproveEachConnection`	Prompt on the PC to allow/deny each connection (default off).
`IdleTimeoutMinutes` / `MaxSessionMinutes`	Auto-disconnect on idle / total time (0 = off).
`PublicRequiresClientCert`	Refuse public source addresses unless mutual TLS is on (default `true`).

Editing the file while the server runs is safe for most keys (they are read when the Security dialog is closed or the server starts); restart the server after editing to be sure.

7. Running the server for a signed-in user vs. a service

JVNC Server captures the interactive desktop and injects input as the signed-in user. It is designed to run in the user's session (autostart at sign-in), not as a Windows service. It cannot show the lock screen or log a user in; the machine must be signed in for remote control to work.

To control programs that run elevated (as administrator), run JVNC Server elevated as well (right-click → Run as administrator, or a scheduled task with highest privileges at logon).

8. Ports and multiple servers

One server per machine, one port. If several machines sit behind one router, forward a different external port to each (e.g. 5901 → PC-A:5900, 5902 → PC-B:5900) — or better, use a VPN and skip the port forwards entirely (see the Security Guide).

9. Logs and support information

%APPDATA%\JVNC\server.log and client.log record connections, disconnect reasons with full exception details, security decisions (rejections, bans, approved/unapproved certificates) and, on the client, once-per-second performance figures. Attach both when reporting a problem.