If you only ever connect while someone is logged in and clicks 'allow', you don't have true unattended access. Running the VNC Viewer server as a Windows service lets you reach a machine at any time, including the login screen — essential for servers, kiosks and remote workstations.
Why service mode matters
A normal user-mode server stops when the user logs off and can't see the secure Windows login screen. As a service, the server starts with Windows, survives log-offs and reboots, and can display the login desktop so you can sign in remotely.
Installing the server as a service
- Install VNC Viewer with the server component (see our setup guide).
- Open the VNC Viewer Server admin properties as an administrator.
- Register/install the service so it starts automatically with Windows.
- Set the service to start on boot.
- Set a strong password and enable encryption before relying on it.
Securing an always-on server
Unattended access is powerful, so treat security as mandatory, not optional. A machine that's always reachable is always a target.
- Use a long, unique password — never a shared or default one
- Enable an encryption plugin or require a VPN/SSH tunnel
- Restrict which IPs can connect where possible
- Keep the host patched and monitor connection logs
Always-on convenience only makes sense with always-on security. Lock it down before you depend on it.
Test before you rely on it
Reboot the host and confirm you can connect before it's logged in. Then test that you can reach the login screen and sign in remotely. Only once that works end to end should you treat the machine as truly unattended. If anything misbehaves, the troubleshooting guide covers the common service-mode snags.
Frequently asked questions
It runs the server as a Windows service that starts with the system, so you can connect any time — including at the login screen — without someone logged in to approve it.
Only if you secure it: strong unique password, encryption or a VPN/SSH tunnel, IP restrictions and regular patching.
Yes — that's a key reason to run the server as a service, since a user-mode server can't show the secure login desktop.
Remember: always download VNC Viewer from the
official project source, keep it updated, and never expose a raw VNC port to the
internet without a VPN or SSH tunnel. When you're ready,
head to the download section.
