Product activation for Windows – online & support telephone numbers
To activate Windows 10 using an internet connection: As Windows 10 will automatically activate if you are connected to the internet, you can confirm your activation status by selecting Start > Settings > Update & Security > Activation and looking under Windows.. If online activation fails, first try the activation troubleshooting in Activate Windows 10.
Find or fix a device in your Microsoft account
To check for any security issues, go to Windows Defender settings, select Show details, and check your security status.
Premium features in Outlook.com for Microsoft 365 subscribers
Advanced email security. As a Microsoft 365 subscriber, you get enhanced security tools that help protect your inbox from phishing and malware.
Applies To:
Outlook 2021, Outlook 2021 for Mac, Outlook 2019, Outlook 2019 for Mac, Outlook 2016, Outlook 2013, Outlook.com, Outlook for Android, Outlook for iOS, Outlook for Windows Phone 10, Outlook Mail for Windows 10
XLOOKUP function - Microsoft Support
Use the XLOOKUP function when you need to find things in a table or a range by row. For example, look up the price of an automotive part by the part number, or find an employee name based on their employee ID. With XLOOKUP, you can look in one column for a search term, and return a result from the same row in another column, regardless of which side the return column is on.
Applies To:
Excel for Microsoft 365, Excel for Microsoft 365 for Mac, Excel for the web, Excel 2021, Excel 2021 for Mac, Excel 2019, Excel 2016, Excel for iPad, Excel for iPhone, Excel for Android tablets, Excel for Android phones
Windows help and learning
Find help and how-to articles for Windows operating systems. Get support for Windows and learn about installation, updates, privacy, security and more.
Ways to install Windows 11 - Microsoft Support
Find out how to install Windows 11 on your device, whether you need to use Windows Update, Cloud download, or Local reinstall. Get tips and troubleshooting help from Microsoft Support.
获取 Windows 升级和安装错误的帮助 - Microsoft 支持
若要升级到 Windows 11，需要硬盘上有足够的空间进行安装。 若要查看计算机上可用的硬盘空间，请选择任务栏上的"文件资源管理器 (在Windows 7) 中称为Windows资源管理器，或按Windows徽标键 + E。. 然后，选择“计算机”或“这台电脑”，并在“硬盘驱动器”或“设备和驱动器”下进行查看。
Troubleshoot Outlook mobile issues - Microsoft Support
Make sure your email account is supported. You can add accounts from Microsoft 365, Exchange Online, Exchange Server (2007 SP2, 2010, 2013), Outlook.com (including Hotmail, Live, and MSN), Gmail, iCloud and Yahoo!
Applies To:
Office.com, Outlook for iOS, Outlook for Windows Phone 10
Manage app permissions for your camera in Windows
To use your camera with apps on Windows 10, you'll need to turn on some permissions in Camera settings. Then, you'll need to check your app permissions if you want to use your camera with apps.
Find settings in Windows - Microsoft Support
Find your Windows settings in a snap! Select the Start button, then select Settings .From there, browse the categories or use search to find what you're looking for.