CNET

Mozilla isn't happy with Microsoft's decision to make its Edge the default browser in Windows 10, and the Firefox maker's chief executive has taken his displeasure public.

In an open letter to Microsoft CEO Satya Nadella, Mozilla CEO Chris Beard accuses Microsoft of hobbling users' browser choices by making Edge the default browser in the next generation of its operating system and called on the tech giant to reverse what he called an "aggressive move to override user choice." While noting that it was still technically possible to preserve users' browser settings, Beard charged that the default setting changes have made the option less obvious.

"The upgrade process now appears to be purposefully designed to throw away the choices its customers have made about the Internet experience they want, and replace it with the Internet experience Microsoft wants them to have," he wrote. "It now takes more than twice the number of mouse clicks, scrolling through content and some technical sophistication for people to reassert the choices they had previously made in earlier versions of Windows. It's confusing, hard to navigate and easy to get lost."

Beard said that his company contacted Microsoft to discuss its concerns when it first saw Windows 10, but that its efforts "didn't result in any meaningful progress, hence this letter."

The letter underscores Mozilla's battle to gain more users for Firefox, which ranks a distant third behind Microsoft's Internet Explorer, according to Web traffic numbers recorded by Web tracker Net Applications. In June, Mozilla's browser grabbed a Web traffic share of 12 percent compared with IE's 58.1 percent share. Google's Chrome came in second with 27.2 percent, Net Applications found.

The Windows 10 upgrade doesn't uninstall rival browsers from users' machines, but if users choose to restore Chrome or Firefox as their default browsers, they must launch their browser of choice and go through a couple of steps to instruct Windows 10 of their preference. Illustrating the process, Mozilla created a tutorial to help Firefox user upgrading to Windows 10 restore their browser preferences.

"These changes aren't unsettling to us because we're the organization that makes Firefox," Beard wrote. "They are unsettling because there are millions of users who love Windows and who are having their choices ignored, and because of the increased complexity put into everyone's way if and when they choose to make a choice different than what Microsoft prefers."

Microsoft said in a statement that it was open to making adjustments based on user feedback.

"We designed Windows 10 to provide a simple upgrade experience for users and a cohesive experience following the upgrade," a spokesperson said. "During the upgrade, consumers have the choice to set defaults, including for web browsing. Following the upgrade, they can easily choose the default browser of their choice. As with all aspects of the product, we have designed Windows 10 as a service; if we learn from user experience that there are ways to make improvements, we will do so."

As Windows 10's default browser, Edge is intended to jettison the legacy baggage of Internet Explorer, presenting users with a faster, simpler and sleeker experience like rival browsers such as Google's Chrome.

The company has lofty goals for the new operating system, its first big chance to move beyond the missteps of Windows 8. Microsoft has promised that Windows 10 -- released Thursday as a free upgrade to users of Windows 7 and Windows 8 -- will run across every device, from desktops with large hard drives all the way down to low-cost smartphones with barely a gigabyte to spare.

Updated at 9 p.m. PT with Microsoft statement.