From the screenshot it looks like you have both Acrobat and Reader on the machine and only Reader is disabled.
Check again. If you think the doc is incorrect, post back.
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All browser integration prefs were deprecated with 11.x because browser companies are releasing new versions every 6 weeks or more. It was simply not possible to keep pace without requiring admins to update every few weeks. Moreover, most browsers are gradually phasing out such plugins or at least disable them by default (e.g. Chrome). Many companies provide a browser-specific PDF viewer. Acrobat and Reader share the same config and there's nothing different between the two.
Ben