At the bottom of the page: https://www.webroot.com/us/en/home/products/av also Browser support?
System requirements
PC & Mac Requirements
Microsoft Windows XP 32- and 64-bit SP2, SP3
Windows Vista 32-bit (all Editions), Windows Vista SP1, SP2 32- and 64-bit (all Editions)
Windows 7 32- and 64-bit (all Editions), Windows 7 SP1 32- and 64-bit (all Editions)
Windows 8 32- and 64-bit
Windows 8.1 32- and 64-bit
Windows 10 32- and 64-bit
Mac OS X 10.7 (Lion)
Mac OS X 10.8 (Mountain Lion)
OS X 10.9 (Mavericks)
OS X 10.10 (Yosemite)
OS X 10.11 (El Capitan)
macOS 10.12 (Sierra)
macOS 10.13 (High Sierra)
macOS 10.14 (Mojave)
macOS 10.15 (Catalina)
Minimum Requirements
Intel Pentium/Celeron family, or AMDK6/Athlon/Duron family, or other compatible processor
128 MB RAM (minimum)
10 MB Hard Disk Space
Internet access
Google Chrome 11 and newer
Internet Explorer version 11 and newer (Windows XP IE8)
Microsoft Edge (partial support) When will we have full support?
Mozilla Firefox version 3.6 and newer
Safari 5 and newer
Opera 11 and newer
I don’t know what Mac OS’s are outdated and not supported (Updated) anymore? @ProTruckDriver @Ssherjj
My understanding every macOS from El Capitan and earlier do not receive Security or Software updates.
I found this:
https://computing.cs.cmu.edu/desktop/os-lifecycle.html
I don’t think anyone is running the very old OS’s. Will Webroot work on Lion and Mountain Lion???
Not everyone in this world has a bottomless purse (and it’s not just the computers that have to be purchased, it’s also often the peripherals, and even apps, due to compatibility issues—ask @NicCrockett!). In my case, two of my three computers are using these old OSs: one Windows XP 32-bit and the other Windows 7 64-bit.
As I understand it, Webroot collect enough statistics from their customers to know what OSs they are using. Evidently, a sufficient number of their customers (such as myself, such as @NicCrockett’s company) continue to use these OSs for them to deem it worth their while continuing support for us.