<p><em>While the related SuperUser <a href="https://superuser.com/questions/149056/disable-these-files-might-be-harmful-to-your-computer-warning">question</a> has many solutions for this, they are mostly from the user’s perspective: even the solution related to group policy uses Local Group Policy Editor and is far behind the accepted solution. Therefore, I’ll just add a quick answer on how to do this for the whole network.</em></p>
<p><strong>Create a GPO and enable three settings.</strong> Related descriptions and values explained in citations.</p>
<p>Both <em>Computer Configuration</em> and <em>User Configuration</em> has these:</p>
<ul>
<li></li>
</ul>
<p>Policies \ Administrative Templates \ Windows Components \ Internet Explorer</p>
<ul>
<li></li>
</ul>
<p>Internet Control Panel</p>
<ul>
<li>
<p>Security Page</p>
</li>
<li></li>
</ul>
<p><strong>Intranet Zone Template</strong> > Enabled > Low</p>
<blockquote></blockquote>
<p>This template policy setting allows you to configure policy settings<br>
in this zone consistent with a selected security level, for example,<br>
Low, Medium Low, Medium, or High.</p>
<p>If you enable this template policy setting and select a security<br>
level, all values for individual settings in the zone will be<br>
overwritten by the standard template defaults.</p>
<ul>
<li></li>
</ul>
<p><strong>Site to Zone Assignment List</strong> > Enabled > Show…</p>
<ul>
<li></li>
</ul>
<p>Valuename = <code>yourserver</code></p>
<blockquote></blockquote>
<p>A host for an intranet site, or a fully qualified domain name for<br>
other sites. The valuename may also include a specific protocol. For<br>
example, if you enter <code>http://www.contoso.com</code> as the valuename, other<br>
protocols are not affected. If you enter just <code>www.contoso.com</code>, then<br>
all protocols are affected for that site, including http, https, ftp,<br>
and so on. The site may also be expressed as an IP address (e.g.,<br>
<code>127.0.0.1</code>) or range (e.g., <code>127.0.0.1-10</code>).</p>
<ul>
<li></li>
</ul>
<p>Value = <code>1</code> (Intranet zone)</p>
<ul>
<li></li>
</ul>
<p>Intranet Zone</p>
<ul>
<li></li>
</ul>
<p><strong>Show security warning for potentially unsafe files</strong> > Enabled > Enable</p>
<blockquote></blockquote>
<p>If you enable this policy setting and set the drop-down box to Enable,<br>
these files open without a security warning. If you set the drop-down<br>
box to Prompt, a security warning appears before the files open.</p>