I ran Spyzooka and it found seven 'infections'. Six tracking cookies and one trojan reference in an orphan WinRarSFX registry entry.
The tracking cookies are of no concern as they're from IE which I very rarely use. I killed the whole IE cookie folder. The latest version of Opera detects and prevents use of tracking cookies.
The 'infected' registry entry referred to a program that no longer resides on my system--part of an installation of the crappy BitDefender antivirus program I tried. It slowed my system so I uninstalled it. I guess its uninstallation didn't delete the entry. Calling a registry entry for a program that isn't on the computer an 'infection' is a bit of a stretch.
I deleted the orphan registry entry and reran Spyzooka which found no infections. This tells me that WebRoot is doing its job just fine.

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