Technical Article

Microsoft Edge Internet Explorer Mode: Running Legacy Applications in Modern Browsers

Learn how to configure and use Microsoft Edge's Internet Explorer mode to run legacy applications and websites that require IE compatibility

Microsoft Edge Internet Explorer Mode: Running Legacy Applications in Modern Browsers

In today’s rapidly evolving web landscape, many organizations still rely on legacy applications and internal systems that were built specifically for Internet Explorer. When Microsoft retired Internet Explorer in June 2022, it left many businesses scrambling for solutions. Fortunately, Microsoft Edge includes Internet Explorer mode (IE mode), which provides seamless compatibility for these legacy applications while maintaining the security and performance benefits of a modern browser.

What is Internet Explorer Mode?

Internet Explorer mode is a feature in Microsoft Edge that allows you to run websites and applications that require Internet Explorer compatibility. It uses the same Trident MSHTML engine that powered Internet Explorer, ensuring full compatibility with legacy applications while running within the modern Edge browser.

Key Benefits

  • Full IE Compatibility: Supports ActiveX controls, legacy JavaScript, and IE-specific features
  • Modern Security: Runs within Edge’s security framework
  • Unified Experience: Single browser for both modern and legacy content
  • Enterprise Management: Centralized configuration and deployment options

Enabling Internet Explorer Mode

Method 1: Using Edge Settings (Quick Setup)

  1. Open Microsoft Edge
  2. Navigate to the settings page: 
    edge://settings/defaultbrowser
  3. Scroll down to find “Allow sites to be reloaded in Internet Explorer mode (IE mode)”
  4. Toggle the setting to On
  5. Restart Edge for changes to take effect

Method 2: Using Group Policy (Enterprise)

For enterprise environments, you can configure IE mode using Group Policy:

  1. Download the Microsoft Edge Policy Templates
  2. Import the templates into Group Policy Management Console
  3. Navigate to Computer Configuration > Administrative Templates > Microsoft Edge
  4. Configure the following policies:
    • Configure Internet Explorer integration
    • Configure the Enterprise Mode Site List

Configuring Site Lists

Automatic Site Detection

Edge can automatically detect sites that need IE mode, but you can also configure specific sites:

  1. Go to edge://settings/defaultbrowser
  2. Click “Add” under “Internet Explorer mode pages”
  3. Enter the URL of the site that requires IE mode
  4. Choose the compatibility mode:
    • Default: Uses IE 11 compatibility
    • IE 8: For very old applications
    • IE 7: For legacy enterprise applications

For organizations with multiple legacy applications, create an Enterprise Mode Site List:

<?xml version="1.0" encoding="UTF-8"?>
<site-list version="1">
  <created-by>
    <tool>EMIESiteListManager</tool>
    <version>12.0.0.0</version>
    <date-created>20230101000000</date-created>
  </created-by>
  <site url="https://legacy-app.company.com">
    <compat-mode>IE11</compat-mode>
    <open-in>IE11</open-in>
  </site>
  <site url="https://internal-system.company.com">
    <compat-mode>IE8</compat-mode>
    <open-in>IE11</open-in>
  </site>
</site-list>

Using Internet Explorer Mode

Manual Activation

When you visit a site that needs IE mode:

  1. Click the three dots menu in Edge
  2. Select “More tools”
  3. Choose “Reload in Internet Explorer mode”
  4. The page will reload with IE compatibility

Automatic Activation

Once configured, Edge will automatically detect and load compatible sites in IE mode based on your site list configuration.

Visual Indicators

When a page is running in IE mode, you’ll see:

  • IE icon in the address bar
  • “Internet Explorer mode” text in the title bar
  • Different color scheme for the browser frame

Common Use Cases

1. Legacy Enterprise Applications

Many enterprise applications built for IE are still in use:

  • SAP Business Suite: Older versions require IE
  • Oracle E-Business Suite: Some modules need IE compatibility
  • Custom Internal Tools: Company-specific applications
  • Government Systems: Many government websites still require IE

2. Banking and Financial Applications

Some banking systems still rely on IE:

  • Online Banking Platforms: Legacy security implementations
  • Trading Systems: Financial trading applications
  • Insurance Systems: Claims and policy management tools

3. Manufacturing and Industrial Systems

Industrial control systems often require IE:

  • SCADA Systems: Supervisory control and data acquisition
  • HMI Applications: Human-machine interface systems
  • Equipment Management: Factory floor control systems

Troubleshooting Common Issues

Issue 1: IE Mode Not Available

If IE mode isn’t showing up:

  1. Check Windows Version: IE mode requires Windows 10 version 1903 or later
  2. Verify Edge Version: Ensure you’re using Edge version 79 or later
  3. Check Group Policy: Ensure no policies are blocking IE mode
  4. Restart Edge: Close and reopen the browser

Issue 2: Sites Not Loading in IE Mode

If sites aren’t automatically switching to IE mode:

  1. Add to Site List: Manually add the site to your IE mode site list
  2. Check URL Format: Ensure the URL matches exactly (including protocol)
  3. Clear Browser Cache: Clear Edge cache and cookies
  4. Check Compatibility: Verify the site actually requires IE

Issue 3: ActiveX Controls Not Working

For ActiveX controls:

  1. Enable ActiveX: Ensure ActiveX is enabled in IE mode settings
  2. Check Security Settings: Verify security settings allow ActiveX
  3. Trusted Sites: Add the site to trusted sites list
  4. Administrator Rights: Some ActiveX controls require admin privileges

Best Practices

1. Site List Management

  • Regular Updates: Keep your site list updated with new legacy applications
  • Testing: Test each site thoroughly before adding to production
  • Documentation: Maintain documentation of which sites require IE mode
  • Cleanup: Remove sites that no longer need IE mode

2. Security Considerations

  • Limited Scope: Only enable IE mode for sites that absolutely need it
  • Regular Audits: Periodically review which sites are using IE mode
  • Security Updates: Keep Edge updated for the latest security patches
  • User Training: Educate users about when IE mode is being used

3. Migration Planning

  • Inventory: Create a complete inventory of applications requiring IE
  • Prioritization: Prioritize applications for modernization
  • Testing: Test modern alternatives for legacy applications
  • Timeline: Create a timeline for migrating away from IE dependencies

Advanced Configuration

Registry Settings

For advanced users, you can configure IE mode via registry:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Edge]
"IEIntegrationMode"=dword:00000001
"InternetExplorerModeToolbar"=dword:00000001
"InternetExplorerModeSiteList"=dword:00000001

PowerShell Configuration

Automate IE mode configuration with PowerShell:

# Enable IE mode
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Edge" -Name "IEIntegrationMode" -Value 1

# Set site list location
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Edge" -Name "InternetExplorerModeSiteList" -Value "https://company.com/sites.xml"

Monitoring and Reporting

Event Logs

Monitor IE mode usage through Windows Event Logs:

  • Application logs: Track IE mode activations
  • Security logs: Monitor for security-related events
  • System logs: Track system-level IE mode events

Usage Analytics

Track IE mode usage to plan migrations:

  • Site usage: Which sites are most frequently accessed in IE mode
  • User patterns: Which users rely most on IE mode
  • Time spent: How much time users spend in IE mode

Conclusion

Microsoft Edge’s Internet Explorer mode provides a crucial bridge between legacy applications and modern web standards. By properly configuring and managing IE mode, organizations can maintain compatibility with essential legacy systems while benefiting from modern browser security and performance.

Remember that IE mode is a temporary solution. The long-term goal should be to modernize legacy applications or find modern alternatives. Use IE mode strategically while planning your migration to fully modern web applications.

For the best experience:

  • Configure IE mode only for sites that truly need it
  • Maintain an updated site list
  • Monitor usage and plan for eventual migration
  • Keep Edge and Windows updated for security

With proper configuration and management, IE mode can provide a seamless experience for both modern and legacy web applications.