Internet Explorer is finally, truly dying, and Microsoft wants you ready by 2029

Internet Explorer's days are numbered, and Microsoft is urging businesses to get ready for its ultimate demise by 2029. The once-popular browser is no longer officially supported, having been retired in 2015, but it continues to linger on modern Windows versions through the IE Mode feature. By the end of next year, IE Mode will be officially discontinued, along with the ancient web engine technology it relies on.

Enterprise organizations are strongly encouraged to start preparing for this change now. This involves upgrading or replacing applications that still require Internet Explorer to function on newer operating systems. Microsoft made this plan known in a message sent to the Microsoft 365 admin center, and reiterated that they will announce a new end-of-support notice for IE Mode at least a year in advance. However, the company acknowledges that some modernization efforts might take several years to complete.

Microsoft's Edge browser includes IE Mode, which is essentially a compatibility mode based on Google's Chromium browser engine. This allows Edge to display web pages using Internet Explorer 11's Trident engine. IE Mode, also known as MSHTML, has undergone numerous changes since its introduction in Internet Explorer 4.0. It supports WebGL applets and the now-retired SPDY web communication protocol, as seen in Internet Explorer 11's MSHTML 7.0.

For organizations that don't use any IE-based applets, no action is required after Microsoft sends out the MC1473151 alert. However, if your business relies on IE Mode, you should thoroughly assess your IT infrastructure to identify critical elements that still require it. These applications and websites should be updated, rehosted, replaced, or rebuilt using contemporary web technologies, Microsoft advises.

The company even offers App Assure service to help eligible customers check and improve the compatibility of custom applications with modern Windows platforms.

Microsoft emphasizes that planning early can help your organization identify migration risks and minimize disruption as you move away from IE Mode dependencies.