Install Firefox 41 extension silently

Question

I'm making automatic installer for special Firefox extensions. I have read couple of articles about that, but none of the described methods are not helped.
What I tried to do:

• Placed .xpi file and unpacked unpacked extension directory in %FF_DIR%\browser\extensions
• Placed .xpi file and unpacked unpacked extension directory in %FF_DIR%\extensions
• Placed unpacked extension directory in another directory and added record in registry (HKLM\Software\Mozilla\Firefox\extensions, key is extension id and value is full path to unpacked extension)

In all ways unpacked extension directory was:

• Just random name
• ID from install.rdf #1 ({ec8030f7-c20a-464f-9b0e-13a3a9e97384} for example)
• ID from install.rdf #2 (prism@developer.mozilla.org for example)

And, as i said, all methods don't give me expectable result. Firefox don't show extensions in list and don't show any notification. How can i solve it? What actual method using in current version of FF?
Target browser is Firefox 41.0.1, system - Windows 7 x64
Thanks!

Answer 1

My problem was using for incorrect ID (Both of them were obtained from "targetApplication" sections). Now I was able to install the plug-in by copying .xpi files to %FF_DIR%\browser\extensions.