Why doesn't the Silverlight plugin appear in IE "add-ons"?

Question

Microsoft Silverlight

Good day to all.
One program I needed required the Silverlight plugin installed and included in IE.
I went to the MS website, downloaded the latest version, installed it, but the plugin did not appear in the "add-ons" of IE.
The classic "reinstall / reset IE settings / restart / select "All add-ons"" tried, does not help.
Windows 7 x64, IE 11, Silverlight 5.1
Screenshots:
i.imgur.com/oTBss5W.png
i.imgur.com/qSQJUhx.png (yes, only one "add-on" is available from MS)
Please tell me what could be problem?