Internet Explorer 11’s Enterprise Mode: Preserve Compatibility While Enhancing Speed and Security

One major challenge in common with many Windows XP to Windows 7 migrations is mitigating browser support issues – applications and websites developed for Internet Explorer 6 often had to be redeveloped, upgraded, or sometimes even replaced in order to support Internet Explorer 8 and later. Since Windows 7 shipped with Internet Explorer 8, and Windows XP could be upgraded to that version, it became a “lowest common denominator” platform – organizations could standardize on support for Internet Explorer 8 and theoretically support both their applications on both Windows XP and Windows 7 platforms during a coexistence period.

Unfortunately, subsequent new versions of Internet Explorer didn’t necessarily prompt organizations to upgrade, given the non-trivial need to test compatibility of the new versions across the wide range of websites and applications. This has the potential to create the same problem for upgrades to future operating systems and browsers. For example, Windows 8 ships with Internet Explorer 10 and Windows 8.1 ships with Internet Explorer 11 – meaning that another major compatibility and remediation effort may be needed to move to those platforms.

Fortunately, Microsoft has released an update to Internet Explorer 11 that preserves compatibility with Internet Explorer 8 while allowing upgrades to newer (and theoretically higher performance and more secure) browser versions. Internet Explorer 11’s new “Enterprise Mode” allows the “best of both worlds” – the enhanced speed and security of the new browser version, but with better backwards compatibility with Internet Explorer 8. Enterprise Mode is an emulation mode like the old Internet Explorer Compatibility Mode, but greatly improved, preserving support for some of the proprietary or no longer supported functionality that was available in Internet Explorer 8. Enterprise Mode is available in Windows 7/Server 2008 R2 SP1 and Windows 8.1/Server 2012 R2. Internet Explorer 11 is not available for Windows Vista or Windows 8, so those platforms will not enjoy the functionality.

To take advantage of Enterprise Mode, first ensure that the appropriate security update is installed for your machines. For Windows 7, this is a hotfix for Internet Explorer 11. For Windows 8.1, this is the full Windows 8.1 Update package(s):

Next, create a list of websites that should run in Enterprise Mode. Microsoft has released a tool to create and manage the list, which is stored in XML format. The tool is available here: You can also mandate via this XML list that some sites not be run in Enterprise Mode, so if there are sites that absolutely won’t work in Internet Explorer 8, you can effectively prevent them from ever running in Enterprise Mode for any reason.

Finally, enable Enterprise mode and specify the location of the XML site list using group policy or by configuring registry keys. To use group policy:

  • To allow users to manually run sites in Enterprise mode, change the “Computer Configuration\Administrative Templates\Windows Components\Internet Explorer\Let users turn on and use Enterprise Mode from the tools menu” setting to “Enabled”
    • Optionally, set a URL and port if Internet Explorer should post changes to Enterprise Mode settings back to that location
  • To specify the location of the XML site list, change the “Computer Configuration\Administrative Templates\Windows Components\Internet Explorer\Use Enterprise Mode IE website list” setting to “Enabled” and specify the URL location of the site list.

Registry keys can be set both per-user and per-computer, but the examples below are per-computer:

  • Create a new key: HKLM\Software\Policies\Microsoft\Internet Explorer\Main\EnterpriseMode
  • Create the appropriate new values in the new key:
    • To allow users to manually run sites in Enterprise mode:
      • Value Name: Enable
      • Value Type: String (REG_SZ )
      • Value Data: leave blank to just enable manual Enterprise Mode, or specify a URL and port if Internet Explorer should post to that URL/port to log changes to the Enterprise Mode settings
    • To specify the location of the XML site list
      • Value Name: SiteList
      • Value Type: String (REG_SZ)
      • Value Data: URL or path to XML site list created using the above tool

Regardless of method used to enable Enterprise Mode, the two settings are not mutually exclusive – meaning you can allow users to run sites in Enterprise Mode without specifying a site list, or you can specify a site list while not showing users Enterprise Mode options, or you can allow users to place sites in Enterprise Mode while simultaneously specifying a site list that must be run in Enterprise mode.

Once configured, Internet Explorer will check for the XML site list roughly one minute after being opened. It then loads and caches the site list, so that even when the browser does not have access to the registry specified site list location, Internet Explorer can still reference the list of Enterprise Mode sites. The browser does not check again for an updated XML file until the browser is closed and reopened. XML files created using Microsoft’s tool have a version number, and the local cached copy is updated only if the version number changes.

When visiting a site that is running in Enterprise Mode, whether in the site list or manually set for Enterprise Mode by the user, you’ll see the following icon to the left of the address bar:


Finally, if a site is not specified in the site list, users can enable Enterprise Mode for that site by selecting the “Enterprise Mode” option from the Internet Explorer “Tools” menu (visible by pressing “Alt”):


To sum up, Internet Explorer Enterprise Mode allows organizations to update to the latest, most secure, and highest performing version of Internet Explorer while maintaining better, centrally managed Internet Explorer 8 compatibility. By moving to newer browser versions, organizations can remove the need to develop for older Internet Explorer 8 standards, and can deploy websites and applications that may not support the older Internet Explorer 8 browser. Hopefully, Enterprise Mode can help remove Internet Explorer versions as a blocker for future operating system upgrades.


  • Coyoles August 15, 2014 3:50 pm

    Hello, nice article.

    You wrote “..XML files created using Microsoft’s tool have a version number, and the local cached copy is updated only if the version number changes.

    Can you tell me where the “local cached” version is stored in the system, be a file or a registry key?


    • Andrew Topp August 20, 2014 9:06 am

      Coyoles, when Internet Explorer checks for the site list it does so in one of three places. The first is the Internet Explorer cache container, which to my knowledge isn’t exposed in any kind of readable/editable format to you as a user. If the site list is not found in the cache container, then the user’s local cache is checked – you might be able to find the site list XML there, but in all of my testing, I was unable to find a machine where the file was saved with any obvious name or formatting. Finally, if the site list can’t be found in the cache container or the user’s local cache, then the machine makes a request from the URL or file location specified in the group policy or registry setting described in my original post.

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