Half of the Windows 10 PCs in use by organisations may be affected by Microsoft’s Internet Explorer browser reaching end of life, according to research by IT asset management provider Lansweeper.
An audit of nine million Windows 10 PCs in use by 33,000 organisations in June found that 47% are using version 20H2 or later, on which support for Internet Explorer has ended. The remaining 53% are using versions of the operating system that are already unsupported.
As of its end of life, users of the IE11 desktop application on these versions will be redirected to Edge, Microsoft’s alternative browser. Although Microsoft Edge has an ‘IE Mode’ that allows users to access sites and apps that were developed for the older browser, Microsoft has been encouraging organisations to test their legacy systems on Edge’s IE Mode. Those who haven’t may encounter performance issues following today’s retirement of Internet Explorer.
Microsoft has continued to support Internet Explorer since the launch of Edge in 2015. But in May 2021, it announced that “the Internet Explorer 11 desktop application will be retired and go out of support on June 15, 2022, for certain versions of Windows 10”, namely version 20H2 or later.
At the start of this month, Lansweeper found that 47% of corporate PCs running Windows 10 are using these versions.
In an update, Microsoft clarified that all versions of Windows 10 that predate 20H2 are already out of support, and the redirection from Internet Explorer to Edge will still apply.
"Staying on an unsupported version of Windows 10 will not prevent redirection," the company said. "The IE11 desktop application will be redirected to Microsoft Edge across both supported and unsupported versions of Windows 10."
Microsoft released Windows 11 in October 2021 but Windows 10 is still far more widespread. In April of this year, Windows 11 had a 19.7% share of the Windows install base, according to data from ad network AdDuplex, with the various versions of Windows 10 making up the remaining 80.3%.
Internet Explorer end of life: what happens now?
With the end of life in effect, IE11 users on affected versions of Windows 10 will be 'progressively' redirected to Edge. "To minimise the level of potential business disruption within an organisation at one time, not all devices will be redirected at the same time," Eric Van Aelstyn, product market manager for Microsoft Edge wrote in a company blog post.
"This approach is designed so that you can quickly identify and resolve any potential issues, such as missed sites, before all devices within your organisation are redirected."
Microsoft intends for this "progressive redirection" phase to be complete within a few months. After this, IE will be "permanently disabled" in a future Windows Update. Internet Explorer mode in Microsoft Edge will be supported through to at least 2029.
Companies should not proactively delete IE11 from their employees' devices, Van Aelstyn warned in an update last month. "Internet Explorer (IE) mode [in Edge] relies on Internet Explorer 11 (IE11) to function. Uninstalling or removing IE11 will cause IE mode to no longer work."
Although Edge's IE Mode can support sites and apps built for Internet Explorer, Microsoft advised IT departments to test them before support ended. "We recommend testing as thoroughly as you can with pilot groups of users... prior to your broader internal retirement/disablement activities," it said.
Many organisations may be running legacy sites and apps that could encounter difficulties after the switch to Microsoft Edge. In a blog post in 2021, Sean Lyndersay, general manager for Microsoft Edge Enterprise, said that he expected organisations to have a "surprisingly large set of legacy Internet Explorer-based websites and apps, built up over many years".
"We found that enterprises have 1,678 legacy apps on average," he wrote.
Why is Microsoft ending support for Internet Explorer?
Internet Explorer once dominated the web browser market, reaching a peak market share of 96% in 2001. It has fallen dramatically in popularity since then, overtaken by Firefox and, more recently, Google Chrome.
Microsoft launched Edge in 2015 to reverse that decline. In 2020, after the first version of the browser failed to do so, Microsoft rebuilt Edge using Chromium, Google's open source version of Chrome. Since then, Edge's share of the desktop browser market has grown from 0.02% to 9.54%, according to figures from GlobalStats.
Meanwhile, IE11's market share has fallen from 12% in 2014 to less than 1% in 2022.
Microsoft has continued to support Internet Explorer until now. When announcing it would be discontinuing IE11, it provided three reasons: improved compatibility, user productivity and security.
Edge's security features include Password Monitor, which scans the dark web for evidence that the users' passwords might have been leaked online.