A similar question as been asked for example here.
Anyawy my need is not to open in browser the contents on the folder, like this:
<a href="file:///D:/Tools/">Open folder</a>
(bwt the above works on Chrome, it opens D:\Tools in my machine)
What I would like to achieve is opening the folder explorer at the given address (in case of Windows opening Windows Explorer at D:\Tools.
The scenario is: the web application (php) knows which folder to open, the user clicks a button and the folder is opened in folder eplorer. Somehow a manual workaround is:
I realized that using Internet Explorer the behavior is my desired one:
1) user clicks on
<a href="file:///\\SERVER\FILES\Folder1">\\SERVER\FILES\Folder1</a>
2) windows explorer opens at \\SERVER\FILES\Folder1
So what i want to achieve it is possible only in Internet Explorer (without exploring plugins and tricks). On other browsers clicking on the link will just let the browser render a read only visualization of the folder, so while using other browsers the user can copy the link text and paste it in the folder explorer.
This solution is not perfect but it suits my need.