Requirements
Windows 10 or 11 (64-bit)
Win11 24H2 supported — the launcher applies the bundled BattlEye fix.
Steam account
Required for Arma 2 OA identity — the server uses Steam auth.
Arma 2 + Arma 2: Operation Arrowhead (Steam)
Both titles required — A2OA on Steam. Often on sale bundled as Combined Operations.
~5 GB free disk space
For Arma 2 OA + mod files.
How to install
Buy both Arma titles on Steam
You need Arma 2 and Arma 2: Operation Arrowhead. Install both through Steam before running the mod installer.
Run the launcher, click INSTALL
Download DayZModClassic.exe (~69 MB, bundles its own runtime) and run it from anywhere. It detects your Steam library, then INSTALL downloads the mod files (~206 MB) and the BattlEye Win11 fix straight into your Arma 2 OA folder.
Connect
Select a server and click PLAY. Steam must be running. When a patch ships, the button reads UPDATE and only the changed files download.
The launcher is unsigned (code-signing certs run ~$200/yr). Windows will show "Windows protected your PC" on first run.
- Click More info on the warning.
- Click Run anyway.
Verify the SHA-256 hash below matches if you want to confirm the file is untampered.
File hashes
Troubleshooting
Launcher won't run
If SmartScreen blocks it, click More info then Run anyway. If it opens and immediately closes, check for a second copy already running in the tray.
Launcher says "Missing addons"
Arma 2 is not installed or Steam returned a bad path. Make sure both Arma 2 and A2OA are fully installed via Steam, then click INSTALL again in the launcher.
BattlEye kicks on connect
The launcher installs the Dwarden Win11 24H2 BE fix with the mod. If kicks persist, check the launcher's STATUS panel shows all green and Steam is running when you connect.
Still stuck?
See the full troubleshooting guide or ask in Discord.
Run your own server
The server bundle includes portable MySQL 5.5, HiveEXT 0.9.6.14, the mission, server configs, and INSTALL_SERVER.ps1 — a script that handles firewall rules, MySQL service registration, and dep installs on a fresh Windows Server box.
See the hosting guide for full steps. To get your server listed in the launcher, post in Discord with your public IP and port.