Files required for a dedicated Arma III server on Windows.
DirectX https://www.microsoft.com/en-us/download/details.aspx?id=35
Visual C++ Redistributable 2013-2015 x86 and x64 versions
https://www.microsoft.com/en-ca/download/confirmation.aspx?id=40784
https://www.microsoft.com/en-ca/download/details.aspx?id=48145
You also need steamcmd from here -> https://developer.valvesoftware.com/wiki/SteamCMD
3 Directories are required. You can use any local, virtual or network attached drive.
E:\A3Files
E:\steamcmd
E:\A3S1
Install all required files on your server
Install steam from steamcmd.exe
Edit serverupdate.cmd to suite your needs, install required files and launch server