Mozilla finds it unfair Microsoft is making their own Edge browser the default Internet browser for Windows 10. Mozilla's CEO wants the public to know about it by sending a letter to Microsoft.

Mozilla CEO Chris Beard sent an open letter to Microsoft CEO Satya Nadella accusing Microsoft of preventing users from choosing their own browser and being forced to use Microsoft's built-in browser. Beard says Windows 10 users are instead given the default browser of Microsoft Edge.

Beard says Microsoft needs to reverse this "aggressive move to override user choice" and change the settings so that the Edge browser is not automatically chosen as the default browser. Beard noted it is still possible to change settings to pick another default browser, but it is less obvious for users to do this because of the way Microsoft has preselected Edge as the browser of choice.

"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." 

Before the official release of Windows 10, Beard said his company had contacted Microsoft to express some of the concerns they had. He said his efforts "didn't result in any meaningful progress, hence this letter." 

Mozilla wants to gain more users for its Firefox browser as it currently stands in a distant third behind Microsoft's Internet Explorer and Google Chrome.

Upgrading to Windows 10 does not uninstall other web browsers, but users will have to tell Windows 10 they prefer one of these other browsers to be their default choice. Mozilla published a tutorial to show users how to make Firefox their default browser.

Microsoft addressed the complaints of Beard on web browser defaults.

"During the upgrade, consumers have the choice to set defaults, including for web browsing," the tech company said in a statement CNET.com obtained. "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."