Installing on Windows

Download the 64-bit installer from the releases page: lmc-<version>-win64.exe (for example lmc-1.3.17-win64.exe). Windows 10 and 11 (64-bit) are supported.

Install

1. Run the downloaded .exe. The installer needs administrator rights, so confirm the User Account Control prompt (“Do you want to allow this app to make changes to your device?”).
2. Follow the wizard: Welcome → License → install folder (default C:\Program Files\LAN Messenger) → Install.
3. On the Finish page leave Start LAN Messenger checked to launch right away.

The installer creates Start menu shortcuts (for all users), registers the uninstaller, applies the start-at-login setting, and creates the Received Files folder in your Documents. If a previous version is already installed, the installer asks to remove it first — settings and history are kept.

SmartScreen warning

The installer is not code-signed, so Windows SmartScreen may block the first launch with a “Windows protected your PC” warning. This is about the missing publisher signature, not a broken download. Click More info, then Run anyway — the approval is one-time per install.

A paid certificate only proves who published a file. With LAN Messenger you can check what is inside instead. The full source is open under GPL-3.0, and every release is built automatically on GitHub servers, on a fresh machine for each run, then published untouched. Open code plus a clean build on infrastructure run by Microsoft is arguably a stronger guarantee than a signed binary from some vendor website.

Firewall

The installer adds two inbound allow rules named LAN Messenger (TCP and UDP, bound to the installed lmc.exe, private profile only) — no manual port setup is needed on a home or office network:

Direction	Port	Used for
Inbound UDP	50000	Peer discovery (multicast group 239.255.100.100 plus directed broadcast)
Inbound TCP	50000 by default	Messages and file transfers (or the TCP port set in Preferences → Network → TCP Port)

Two things still hide peers:

• Public networks. The installer rules cover the private profile only. If your network is set to Public (Settings → Network & internet → Wi-Fi/Ethernet → network → Private), switch it to Private so the rules apply.
• VPN, Wi-Fi client isolation, different subnets. Machines must reach each other directly on the local network, not only the internet. For machines on different subnets, add the remote broadcast addresses under Preferences → Network → Broadcast.

Silent install

For deploying to many machines, run the installer with the NSIS silent flags from an elevated command prompt (/D= must be the last parameter, without quotes):

lmc-1.3.17-win64.exe /S /D=C:\Program Files\LAN Messenger

To install without admin rights prompts into a user-writable folder:

lmc-1.3.17-win64.exe /S /D=C:\LAN-Messenger

Update and uninstall

Install the new version over the old one with the same installer; settings and history are kept. To remove, use Settings → Apps → LAN Messenger → Uninstall, the Start menu Uninstall LAN Messenger shortcut, or uninst.exe in the install folder. The uninstaller asks whether to also delete history and preferences; uninstall keeps them unless you check those boxes. Silent uninstall:

"C:\Program Files\LAN Messenger\uninst.exe" /S

Settings live in %APPDATA%\LAN Messenger\LAN Messenger.ini (chat history, avatars, and groups sit next to it — see the INI file reference).

If it still doesn’t start

Open an issue with your Windows version and build (10 or 11), the app version, the exact installer file name, and the exact message text or screenshot Windows shows.