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Check the recent sign-in activity for your Microsoft account
If you get an email about unusual activity on your Microsoft account, or if you’re worried that someone else might have used your account, go to the Recent activity page.You’ll see when your Microsoft account was signed in during the last 30 days, along with any device or app-specific info.
Applies To: Microsoft account dashboard
在电脑或 Mac 上下载并安装或重新安装 Microsoft 365 或 Office 2021 - Microsoft 支持
准备好安装了吗? 在开始之前,请确保电脑或 Mac 满足 系统要求。. 如果你已兑换产品密钥,只需重新安装应用,或者知道你已通过工作或学校分配了许可证,则可以跳到登录部分 ,下载并安装 Microsoft 365 或 Office。 但是,如果是 首次 安装 Microsoft 365 或 Office,可能需要先执行一些步骤。
Applies To: Office 2021, Office 2021 for Mac, Office 2019, Office 2019 for Mac, Microsoft 365 for home, Office for business, Office 365 Small Business, Microsoft 365 admin, Office 365 operated by 21Vianet, Office 365 operated by 21Vianet - Admin, Microsoft 365 for Mac, Office 365 Germany - Enterprise, Office 365 Germany - Enterprise admin, Office.com
Count how often a value occurs - Microsoft Support
The COUNTIFS function is similar to the COUNTIF function with one important exception: COUNTIFS lets you apply criteria to cells across multiple ranges and counts the number of times all criteria are met. You can use up to 127 range/criteria pairs with COUNTIFS. The syntax for COUNTIFS is: COUNTIFS(criteria_range1, criteria1, [criteria_range2, criteria2],…)
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 2019 for Mac, Excel 2016
Repair Outlook Data Files (.pst and .ost) - Microsoft Support
Note: The scan creates a backup file during the repair process.To change the default name or location of this backup file, in the Enter name of backup file box, enter a new name, or choose Browse to select the file you want to use. You may need to run the tool several times in order to repair your Outlook Data File.
Applies To: Outlook for Microsoft 365, Outlook 2021, Outlook 2019, Outlook 2016
LOOKUP function - Microsoft Support
Vector form. The vector form of LOOKUP looks in a one-row or one-column range (known as a vector) for a value and returns a value from the same position in a second one-row or one-column range.. Syntax. LOOKUP(lookup_value, lookup_vector, [result_vector]) The LOOKUP function vector form syntax has the following arguments:. lookup_value Required.A value that LOOKUP searches for in the first vector.
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 2019 for Mac, Excel 2016
Contact Us - Microsoft Support
Contact Microsoft Support. Find solutions to common problems, or get help from a support agent.
Troubleshoot issues with the Xbox app for Windows
Press the Start button on the taskbar, type settings, and then select Settings.; On Windows 10, select Update & Security.On Windows 11, select Windows Update.; On the Windows Update page, select Check for updates to see if any updates are available for your device.; Once the updates have downloaded, select Install now to start the installation.; Following installation, we recommend that you ...
Get help with Windows upgrade and installation errors
To upgrade to Windows 11, you need enough space on your hard drive for the installation to take place. To view how much hard drive space is available on your computer, select File Explorer on the taskbar (known as Windows Explorer in Windows 7) or press Windows logo key + E. Then select Computer or This PC and look under Hard Disk Drives or under Devices and drives.
Join a meeting in Microsoft Teams - Microsoft Support
To learn more, check out the Join a Teams meeting video. Join by link. All you need to join a Teams meeting is a link. Select Join the meeting now in your meeting invite to be taken to a page where you can choose to either join on the web or download the desktop app.. If you already have the Teams app, the meeting will open there automatically.
Applies To: Microsoft Teams
Sign in to SharePoint - Microsoft Support
In the upper left corner of the window, select the app launcher > All apps > SharePoint Tip: If you don't see the SharePoint app under All apps, use the Search box near the top of the window to search for SharePoint.
Applies To: SharePoint in Microsoft 365