Outlook Web App only uses light version in IE

Had a patron that could not "uncheck" Use the light version of Outlook Web App
on their login screen.

They had Internet Explorer 11 on Windows 7.   Solution is to use Compatability View:

To do this, press F10 to display the menu bar, go to the Tools menu in Internet Explorer 11, and then click Compatibility View settings. Then, add the OWA site to the list of sites to be viewed in compatibility view.

From Microsoft Knowledge Base

IE warning message

Using Javascript to show warning only in Internet Explorer Browser:

<script language="javascript">
function getInternetExplorerVersion()
// Returns the version of Internet Explorer or a -1
// (indicating the use of another browser).
{
  var rv = -1; // Return value assumes failure.
  if (navigator.appName == 'Microsoft Internet Explorer')
  {
    var ua = navigator.userAgent;
    var re  = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
    if (re.exec(ua) != null)
      rv = parseFloat( RegExp.$1 );
  }
  return rv;
}
function checkVersion()
{
  var msg = "<p>Internet Explorer Users:<br> You will get a popup warning message (view content that was delivered securely).  You can <a href='http://blogs.msdn.com/b/askie/archive/2009/05/14/mixed-content-and-internet-explorer-8-0.aspx' target='_blank'>change IE settings</a> to avoid this warning, or use Firefox or Chrome instead.</p><p>&nbsp;</p>";
  var ver = getInternetExplorerVersion();

  if ( ver > -1 )
  {
    if ( ver >= 8.0 )
     
  document.write( msg );
  }

}

checkVersion();       


function getInternetExplorerVersion()
// Returns the version of Internet Explorer or a -1
// (indicating the use of another browser).
{
var rv = -1; // Return value assumes failure.
if (navigator.appName == 'Microsoft Internet Explorer')
{
var ua = navigator.userAgent;
var re  = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
if (re.exec(ua) != null)
rv = parseFloat( RegExp.$1 );
}
return rv;
}
function checkVersion()
{
var msg = "
Internet Explorer Users: You will get a popup warning message (view content that was delivered securely).  You can change IE settings to avoid this warning, or use Firefox or Chrome instead.

";
var ver = getInternetExplorerVersion();

if ( ver > -1 )
{
if ( ver >= 8.0 )

document.write( msg );
}

}

checkVersion();       

</script>