如果这是你第一次安装 Microsoft 365，则可能需要先执行一些设置步骤。展开下面的 “了解详细信息”部分。 但是如果是重新安装 Microsoft 365，且已兑换了产品密钥并拥有与 Microsoft 365 相关联的帐户，请转到“登录并安装 Office”的部分。

Note: To upgrade to Windows 11, devices should meet the Windows 11 minimum system requirements.Some Windows 10 features aren't available in Windows 11. System requirements to experience some Windows 11 features and apps will exceed the Windows 11 minimum system requirements.Find Windows 11 specs, features, and computer requirements

重要: 在选择从媒体启动之前，应验证设备是否满足最低系统要求，因为满足后才允许安装 Windows 11，如果你至少具有 TPM 1.2（而不是最低系统要求的 TPM 2.0），它将不会根据处理器的系列和模型验证处理器是否在批准的 CPU 列表上。

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.

If your PC is running slowly, the following suggestions might help speed things up. The tips are listed in order, so start with the first one, see if that helps, and then continue to the next one if it doesn’t.

Learn how to update Windows to ensure your device operates smoothly and securely with the latest features.

Learn how to remove malware from your PC. Use Microsoft Defender Antivirus in Windows 10 or Windows 11 to scan your PC for malware, viruses, or other threats.

Examples. Following are examples of some common nested IF(AND()), IF(OR()) and IF(NOT()) statements in Excel. The AND and OR functions can support up to 255 individual conditions, but it’s not good practice to use more than a few because complex, nested formulas can get very difficult to build, test and maintain.

Important: Before trying any of the solutions below, make sure you back up your personal files. You can back up your Windows PC, or insert a USB drive and use File Explorer to drag and copy important files to the USB drive.If you’re signing into Windows with a Microsoft account, your system settings will be automatically restored after updating, once you’re connected to the internet.

How to open the Camera app in Windows. To open up your webcam or camera, select the Start button, then select All apps, and then select Camera in the list of apps. If you have multiple cameras, you can switch between them by selecting Change Camera at the top right once the Camera app is opened.. Open Camera