If you're looking for Help on specific Excel Add-ins, such as Solver or Inquire, see Help for Excel for Windows add-ins. If you're looking for additional help with Excel add-ins using the COM Add-ins dialog box, see Add or remove add-ins in Excel. Get a Microsoft 365 Add-in for Excel.

Activate Microsoft 365 or a non-subscription version of Office. When you start an Microsoft 365 app that's not activated, you'll be prompted to sign in to Microsoft 365. Be sure to sign in using the Microsoft account, or work or school account, that you used to buy or subscribe to Microsoft 365.

If you can't find a file on your computer or you accidently modified or deleted a file, you can restore it from a backup (if you're using Windows backup) or you can try to restore it from a previous version. Previous versions are copies of files and folders that Windows automatically saves as part of a restore point.

Learn how to add user accounts in Windows 10 and Windows 11. With an account, each person has separate files, browser favorites, and a private desktop.

You can use installation media (a USB flash drive or DVD) to install a new copy of Windows, perform a clean installation, or reinstall Windows. To create installation media, go to the software download website, where you'll find step-by-step instructions.

Copilot not only helps you create new content, but it also helps you transform your existing content into a document you can be proud of. With text already in your document, highlight the text that you would like to rewrite or transform into a table. In the left margin next to your text, select the Copilot icon.

For guidance on how to locate the Apps button to access add-ins while reading or composing a mail item, see Use an add-in in Outlook. In the Apps page, search for the add-in you want from the available list. Alternatively, if you're after a specific add-in, enter its name in the search box.

您使用 Microsoft Teams （免费版）可能须受您组织政策（如有）的约束。请将您的隐私咨询（包括任何数据主体请求）发送至您所在组织的管理员。

You can directly install add-ins from this page or select More Add-ins to explore. In the Office Add-ins box, click Store tab. Browse for the add-in you want. You can browse the whole store by selecting All or by a specific category such as Productivity.

When you install the web version of Outlook as a progressive web app, you can do things like pin and launch the web version of Outlook from your computer's home screen or task bar and access your account while you're offline.