Generally, if you bought a physical copy of Windows, the product key should be on a label or card inside the box that Windows came in. If Windows came preinstalled on your PC, the product key should appear on a sticker on your device. If you’ve lost or can’t find the product key, contact the manufacturer. To ensure your product key is ...

A collection of powerful productivity apps you can use anywhere. Organize your life, expand your creativity, and protect what’s important. Buy or try Microsoft 365. Get help for the account you use with Microsoft. Find how to set up Microsoft account, protect it, and use it to manage your services and subscriptions.

Contact Microsoft Support. Find solutions to common problems, or get help from a support agent.

Learn how to run Windows Update Troubleshooter to resolve errors downloading or installing Windows updates.

Sign in to Microsoft 365 admin center with your Microsoft 365 admin account, and select Support > Help and support, enter your question and select Contact support. If you're an admin on the account you can also call (800) 865-9408 (toll-free, US only). If you’re outside the United States, see the global support phone numbers. Business Assist ...

使用产品密钥激活 Windows. 产品密钥是由 25 个字符组成的代码，如下所示：. 产品密钥：XXXXX-XXXXX-XXXXX-XXXXX-XXXXX. 在安装期间，系统会提示你输入产品密钥。. 或者，安装后，若要输入产品密钥，请选择“ 开始 ”按钮，然后选择 “设置 > 系统 > 激活 > 更新产品密钥 ...

若要以其他语言安装 Microsoft 365 或安装 64 位版本 ，请使用下拉列表查找更多选项。. 选择所需语言和位版本，然后选择“ 安装 ”。. 现在你已准备好安装 Microsoft 365。. 请在下方选择与你要尝试安装的版本对应的选项卡。. Office 2019 或 2016 for PC Office 2016 for Mac ...

获取 Windows 操作系统的官方支持和帮助信息，以及如何使用 Windows 的指南。

將您的 Surface 送修. 如果上述解決方案都無法解決問題，您可以將 Surface 送修。 如果您決定將 Surface 送修，請移至裝置服務與維修，然後使用您的 Microsoft 帳戶登入。 如果您的裝置已註冊，請選取該裝置並依照指示操作。

如何在 Windows 中切换用户 (帐户) 选择“ 开始 ”，选择并按住 (，或右键单击) 帐户名称图标 (或图片) ，然后选择“ 切换用户 ”。. 了解如何在 Windows 中的不同用户 (帐户) 之间切换。.