Which Web browser do you use on your computer? If it’s Firefox or Chrome, you probably won’t appreciate what Windows 10 does when you install it. In fact the CEO of Mozilla, the company that makes Firefox, has penned a scathing open letter to Microsoft CEO Satya Nadella.

Chris Beard, CEO of Mozilla, is irked that when users install Windows 10 using “Express settings,” the new Microsoft operating system makes its new browser, named Edge, the default Web browser.

It doesn’t matter if your default browser was Firefox (or Chrome) prior to the installation; you’re getting Edge. And it’s not as simple to change your default browser as it used to be.

One way to keep (or change) your default browser is to choose “Custom” settings instead of “Express” settings during your Windows 10 installation; this will let you pick your default browser during the installation. But if you’ve already upgraded, you might expect the usual “Firefox is not currently set as your default browser. Would you like to make it your default browser?” prompt. That’s always worked before, but with Windows 10 there are a couple more steps to back away from the Edge.

To change your default browser from Microsoft Edge, open up your browser of choice. When you see the prompt asking if you’d like Firefox or Chrome to be your default browser, affirm that you would by clicking the “Use Firefox/Chrome as my default browser” button.

The “Settings” app will launch with the “Choose default apps” tab open. Scroll down to where it says “Web browser” and click on Microsoft Edge. You’ll then see all the browsers on your PC, and you can choose your favorite as the default.

It doesn’t take much work, really, but the process isn’t exactly intuitive. As the Mozilla chief wrote to the Microsoft chief, “It’s confusing, hard to navigate and easy to get lost.”

Still, it’s understandable that Microsoft wants you to use its new browser on the free operating system it just gave you.