Microsoft Corporation is an American multinational technology conglomerate headquartered in Redmond, Washington. The company became influential in the rise of personal computers through software like Windows and has since expanded into areas such as Internet services, cloud computing, artificial intelligence and video gaming among others. For Microsoft 365 or Office apps installed on a Windows PC: If you're not already in a Microsoft 365 or Office file or document, open an app such as Word or Excel, and open an existing file, or create a new one. Select File Account (or Office Account if you're using Outlook). If you're not already signed in, click Sign In. In the Sign in window, type the email address and password you use. Contact Microsoft customer support The type of support Microsoft provides depends on the product you're calling about and if you have a product for home or for business use. It can also depend on if you want help for an issue with a service like OneDrive or Outlook.com, or help with Windows, but you don't have an existing Microsoft 365. Get access to free online versions of Outlook, Word, Excel, and PowerPoint. Sign-in options Terms of use Privacy & cookies. Sign in to check and manage your Microsoft account settings with the Account Checkup Wizard. Access and manage your Microsoft account, subscriptions, and settings all in one place. At Microsoft our mission and values are to help people and businesses throughout the world realize their full potential. Explore Microsoft products and services and support for your home or business. Shop Microsoft 365, Copilot, Teams, Xbox, Windows, Azure, Surface and more. Microsoft 365 includes Word, Excel, PowerPoint, Outlook, Teams, and OneDrive, with Microsoft Copilot built in to help you create, communicate, and summarize information. Formerly Office 365.