Step 1: Download the agent installer
Head to the Nessus agent download page:
Search for NessusAgent-7.6.3-x64.msi and download it keep a note where you've saved it. (If you're running an older version of Windows, download NessusAgent-7.5.1-Win32.msi)
Step 2: Install, configure and link the agent
To configure each device for scanning you'll need two pieces of information, your Prefix and a Key. You can find these in the Internal Scanning section of the settings page inside the Intruder portal:
Calculate your DeviceName as follows:
DeviceName = Prefix_TargetName
... where TargetName is what you'd like the target to be called in the portal.
For example, if your Prefix is DQEGBQUAAAc and your want to name your device 'paul-laptop':
DeviceName = DQEGBQUAAAc_paul-laptop
Once you have the above information ready, open a Command Prompt (cmd.exe) as Administrator and run the following command - modifying the path to the agent installer file accordingly:
msiexec /i C:\Users\[your name]\downloads\NessusAgent-7.5.1-x64.msi NESSUS_SERVER="cloud.tenable.com:443" NESSUS_KEY=Key NESSUS_NAME=DeviceName /qn
If you're on Windows 7 x64 Enterprise, Windows 8 Enterprise, and Windows Server 2012, please now reboot your machine.