Hi
I created a blank template file (Rhino.3dm) in folder C:\Windows\ShellNew\Rhino.3dm
Also I changed the registry keys
[HKEY_CLASSES_ROOT.3dm]
@=“Rhino 3-D Model”
[HKEY_CLASSES_ROOT.3dm\ShellNew]
“Filename”=“Rhino.3dm”
@=“Rhino 3-D Model”
[HKEY_CLASSES_ROOT\Rhino5x64.Document]
@=“Rhino 3-D Model”
But a new Items does not appear in the context menu Windows
This is right
…
and example for linked file in registry in Win7x86 (that works here)
Stringkey = FileName
Value = Rhino.3dm (Your rhino file)
…
Last step → logoff and logon, or restart pc
Hi Eddi!
and thanks so muсh 
But by trial and errors I found some other way.
I used the path to my templates in Rhino.
<img src="https://global.discourse-cdn.com/mcneel/uploads/default/original/3X/0/3/03dbbdc3e93bb95942629ab1aa6727bfb2df2214.jpg" width="400" height="308">
1.3dm for the convenience of a name for the new file
"FriendlyTypeName"="1"
But the main error (While it worked in Rhino 4)
[HKEY_CLASSES_ROOT\Rhino 3d model] Now in Rhino5 this section in the registry is not
[HKEY_CLASSES_ROOT.3dm]
@=“Rhino 3-D Model”
I replaced to
[HKEY_CLASSES_ROOT.3dm]
@=“Rhino5x64.Document”
[HKEY_CLASSES_ROOT\.3dm]
@="Rhino5x64.Document"
"Content Type"="application/3dm"
[HKEY_CLASSES_ROOT\.3dm\OpenWithProgids]
"Rhino5x64.Document"=""
@="Rhino 3-D Model"
[HKEY_CLASSES_ROOT\.3dm\ShellNew]
"FileName"="C:\\Users\\leex\\AppData\\Roaming\\McNeel\\Rhinoceros\\5.0\\Localization\\en-US\\Template Files\\Small Objects - Millimeters.3dm"
and
Rhino5x64.Document
[HKEY_CLASSES_ROOT\Rhino5x64.Document]
@=“Rhino 3-D Model”
“FriendlyTypeName”=“1”
[HKEY_CLASSES_ROOT\Rhino5x64.Document\DefaultIcon]
@="\"C:\\Program Files\\Rhinoceros 5 (64-bit)\\System\\Rhino.exe\",1"
[HKEY_CLASSES_ROOT\Rhino5x64.Document\shell]
@="open"
[HKEY_CLASSES_ROOT\Rhino5x64.Document\shell\open]
@="Open with Rhinoceros 5 (64-bit)"
"FriendlyAppName"="Rhinoceros 5 (64-bit)"
[HKEY_CLASSES_ROOT\Rhino5x64.Document\shell\open\command]
@="\"C:\\Program Files\\Rhinoceros 5 (64-bit)\\System\\Rhino.exe\" \"%1\""
