How to Show 'Sign in as Different User' in SharePoint 2013

SharePoint 2013 adds many new features, including improvements to Lists, Sites, and Pages, as well as a variety of changes pertaining to user interface and locations. In some cases, these changes can cause difficulties in using your sites.  In this article, we will take a look at how to show the Sign in as Different User menu item on a site in SharePoint 2013. As you know, the Sign in as Different User menu item on a site is used for logging on to the site using different user accounts. Consequently, this option cannot be hidden; we need to have this feature to support certain tasks. This walkthrough shows you how to enable the Sign in as Different User menu item on a site in SharePoint 2013.

First let's talk about the user interface involved in the process.  In SharePoint 2010, it was a default shown in the drop-down list for user navigation:

With SharePoint 2013, we are not provided the Sign in as Different User menu item as a default:

This is disadvantageous, but don't worry, I'll show you how to configure it within five minutes. 

Step 1:

Go to the welcome.ascx file in 'C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\TEMPLATE\CONTROLTEMPLATES':

Step 2:

Add the code below to the welcome.ascx file in whichever place you prefer (i.e., in what order you want the link to appear).

<SharePoint:MenuItemTemplate runat="server" ID="ID_LoginAsDifferentUser"
Text="<%$Resources:wss,personalactions_loginasdifferentuser%>"
Description="<%$Resources:wss,personalactions_loginasdifferentuserdescription%>"
MenuGroupId="100"
Sequence="100"  UseShortId="true" /> 

For example, see the picture below:

Step 3:

Go to your site and click Refresh, at which point you you will see that Sign in as Different User is now an option:

Good Luck!