Warning: Excel provides the DATEDIF function in order to support older workbooks from Lotus 1-2-3.The DATEDIF function may calculate incorrect results under certain scenarios. Please see the known issues section of this article for further details.

Microsoft support is here to help you with Microsoft products. Find how-to articles, videos, and training for Microsoft Copilot, Microsoft 365, Windows, Surface, and more.

Discusses the release of the Malicious Software Removal Tool (MSRT) to help remove specific prevalent malicious software from Windows-based computers.

You can resolve problems with Microsoft Authenticator by checking the tips in this article and reviewing some of the known errors.

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.

With online threats getting more advanced day by day, it is important to prioritize the safety of your web browsing. Microsoft Edge offers several features and practices that can enhance your online security and protect your personal information.

Get help with signing in, changing passwords, creating and sending mail, deleting mail, creating folders, and more in Outlook on the web.

Learn how to unlock your Microsoft account and resolve 'account has been locked' error message.

Learn how to change settings to enable Secure Boot if you are not able to upgrade to Windows 11 because your PC is not currently Secure Boot capable.

Get answers to some basic questions about what two-step verification is, and how to set it up and use it to help keep your Microsoft account more secure.