Tip: If you're a Microsoft 365 Family or Personal subscriber you get Microsoft Defender, our advanced security software for Windows, Mac, iOS, and Android, as part of your subscription.Learn more at Getting started with Microsoft Defender.

What is a security key? We currently support several designs and providers of security keys using the Fast Identity Online (FIDO2) passwordless authentication protocols. These keys allow you to sign in to your work or school account to access your organization's cloud-based resources when on a supported device and web browser.

If you need to sum a column or row of numbers, let Excel do the math for you. Select a cell next to the numbers you want to sum, select AutoSum on the Home tab, press Enter, and you’re done. When you select AutoSum, Excel automatically enters a formula (that uses the SUM function) to sum the numbers. Here’s an example.

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New or classic Outlook for Windows desktop apps Classic Outlook for Windows is a desktop app included with Microsoft 365 Personal or Family subscriptions or non-subscription versions of Office such as Office Home & Business. New Outlook for Windows is available free on Windows devices or as a free download.If you don't already have new Outlook, you can download it from the Microsoft Store ...

Learn how to use Word in Windows with training guides, articles, and videos from Microsoft Support.

Select the Start button, then go to Settings > Personalization > Lock screen, and select Screen saver settings.In the Screen Saver Settings window, choose a screen saver from the drop-down list. Change your screen saver settings

Note: If you have a current version of Microsoft 365, then you can input the formula in the top-left-cell of the output range, then press ENTER to confirm the formula as a dynamic array formula. Otherwise, the formula must be entered as a legacy array formula by first selecting the output range, input the formula in the top-left-cell of the output range, then press CTRL+SHIFT+ENTER to confirm it.

A Desktop Alert is a notification that appears on your desktop when you receive a new email message, a meeting request, or a task request. By default, Desktop Alerts are turned on.

Windows 10 puts notifications and quick actions in Action Center—right on the taskbar—where you can get to them instantly. Select Action Center on the taskbar to open it. (You can also swipe in from the right edge of your screen, or press Windows logo key + A.). Notifications at a glance