Hello ! I'm Aymeric, an independent advisor, and I'm here to help !
At the moment, Microsoft Edge does not support detaching the Copilot sidebar into a separate, resizable window. Earlier versions allowed detaching the sidebar, but this feature has been removed in recent updates.
Sorry for the inconvenience...
However, here's a workaround that could work out for you. Inside Microsoft Edge, you can install websites as applications. Sites become applications independent of Microsoft Edge, with their own window and icon on the taskbar.
You can do this for Microsoft Copilot.
In Edge, head to https://copilot.microsoft.com .
In the top-right corner of the screen, click on the three horizontal dots and choose "Apps" > "Install this site as an app". Follow the steps and click on "Install".
Copilot will now be in a standalone window.
Please let me know if you have any other question !