Notes: If you know your password, but just want to change it, go to account.microsoft.com Security tab, and select Change my password. If you know your username and password but they have stopped working, read My username and password have stopped working.

Which browsers work with Office for the web and Office Add-ins. How to sign in to Outlook on the web. Fix account settings being out-of-date in Mail or Calendar. Still need help? To get support in Outlook.com, click here or select Help on the menu bar and enter your query.

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.

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

This article applies if you’ve recently made changes to your device hardware and are trying to upgrade to Windows 11. Hardware changes might affect your upgrade eligibility, though you’ll need to take a few steps to see your updated eligibility in Settings.

但如果需要测试多个条件，例如我们假设所有条件都需要为 True 或 False (AND)，或只有一个条件需要为 True 或 False (OR)，或者如果想要检查某个条件是否不 (NOT) 符合你的条件，这时该怎么做呢？这三个函数均可以单独使用，但它们更常见于与 IF 函数成对使用。

If you think someone might have unauthorized access to your account, we can protect you by signing you out from all of your trusted devices. Within 24 hours, you will be signed out of browsers, apps and anywhere else your account is used to sign in, except an Xbox console.

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.

Tip: If you installed the Microsoft 365 apps as part of a suite, such as Office Home and Student or Microsoft 365, search for the suite name.For stand-alone apps search by the app name, such as Project or Visio. In most cases you can't uninstall an individual app if it's included in your Microsoft 365 suite.

Windows devices may get new functionality at different times as Microsoft delivers non-security updates, fixes, improvements, and enhancements via several servicing technologies—including controlled feature rollout (CFR).. Windows will let you know if you need to restart your device to complete an update, and you can choose a time that works best for you to complete that update.