Windows 11 includes a conversational AI-powered assistant called Copilot, which uses cloud-based AI and requires the PC to be online. The app changes and improves continuously. Depending on the PC, one of two Copilot apps is preinstalled: Microsoft Copilot for individuals using personal computers, or Microsoft 365 Copilot for businesses, which includes advanced productivity functionality integrating with Desktop apps like Microsoft Word, Excel, and PowerPoint. The chapter covers Microsoft Copilot, not Microsoft 365 Copilot. Functionality varies because some features are free, while others require an eligible consumer Microsoft 365 subscription. Users must sign in with a Microsoft account to access most features; those using a local account are restricted to basic chat and the Discover feed, which includes a Copilot Daily voice-based news overview. To access exclusive Copilot functionality, users must have a Microsoft 365 Personal, Family, or Premium subscription (a Basic subscription is ineligible) and must be the subscription owner.