To create an HTML link to a UNC path, use the following format for the href attribute of the anchor (a) tag.
<!--
To create an HTML link to a UNC path, use the following format for the
href attribute of the anchor (a) tag.
file://///path/to/unc/share
You must have *five slashes* at the beginning! The first three slashes
are a part of the protocol "file:///" (yes, indeed it is supposed to have
three ... unlike the two in http://, https://, ftp://, etc.). The next two are
the first part of the unc path switched from back-slashes to slashes.
HUGE CAVEAT!!!
This will only work by default in Internet Explorer and only if the user is on
the same network as the UNC path. Meaning, this will not work for a publicly
accessible site. This will only work for an internal intranet-ish site. Only
IE has the file protocol turned on by default. You can get extensions for
Firefox and Chrome that will enable it.
Chrome Extension
https://chrome.google.com/webstore/detail/locallinks/fkkidcgelfcjmebocoaicnelkbnpgpmm
Firefox Extension
https://addons.mozilla.org/en-US/firefox/addon/noscript/?src=search
-->
<!-- UNC Link -->
<a href="file://///computer/share/file.mp4">Watch.mp4</a>
<!-- UNC Link w/ spaces encoded (%20) -->
<a href="file://///computer/share/file%20with%20spaces.mp4">Watch.mp4</a>