Setting up your device
WD ATP is available on Windows 7 SP1 and 8.1 Pro and Enterprise as you can read here and if running Windows 7 SP1 you need to be sure you have installed some updates as also mentioned in the article. To onboard your device you need to install the Microsoft Monitoring Agent (MMA). You need a Windows 10 E5 license assigned to the user when running WD ATP on Windows 7 or 8.1, like you need when running it on a Windows 10 device.
First logon to Windows Defender Security Center via https://securitycenter.windows.com and open the settings. Browse to Machine Management, Onboarding. Select Windows 7 SP1 and 8.1 as operating system. Here you find your Workspace ID and Workspace key which you both need during the installation of the MMA.
Test the WD ATP onboarding
The onboarding of the Windows 7 device was pretty simple, let`s see if the device is already reporting to the Windows Defender Security Center.
On the onboarding tab you also find a detection script you can use to see if the onboarding was succesful.
Switch back to your client device, open the command prompt and run the detection test.
Onboarding of a Windows 7 or 8.1 device is pretty simple and it does work without any issues as far as I have noticed in this short test.