Right-click the Start button (lower-left corner) and select Apps and Features on the pop-up menu. Select the Microsoft 365 or Office product you want to repair and select Modify. Note: This will repair the entire Office suite even if it's just one application you want to repair such as Word or Excel.

When you try to open a workbook in Microsoft Excel for the web, you might see an error message that tells you the extension of your file has changed, or that your file is corrupted and can't be opened. This issue can often be resolved by restoring a previous version of the file using the version history feature.

Before you run the troubleshooter, make sure that you back up the registry and all files in startup folders used by Excel so that you can restore the registry and backed-up files if a problem occurs. You need to be on Windows 10 or higher to run the troubleshooter.

Learn how to use the Gaming Services Repair Tool to troubleshoot installation and update issues with Gaming Services on PC.

You can use Excel to create and edit connections to external data sources that are stored in a workbook or in a connection file. You can easily manage these connections, including creating, editing, and deleting them using the current Queries & Connections pane or the Workbook Connections dialog box (available in previous versions).

Use the Microsoft 365 network connectivity test to measure connectivity between your device and the internet, and from there to Microsoft’s network. View troubleshooter results. After you run any troubleshooter, Get Help provides details on any findings and suggestions for possible remedies.

Find Microsoft Excel help and learning resources. Explore how-to articles, guides, training videos, and tips to efficiently use Excel.

Are you being encouraged to change your ActiveX settings by a pop-up message? If you downloaded the file from a website, be cautious of pop-ups or messages urging you to adjust your ActiveX settings. These are common attack methods and may indicate that the file is unsafe.

Learn how to restore a previous version of a file in OneDrive using the OneDrive website.

To install an add-in that is typically installed with Excel, such as Solver or the Analysis ToolPak, run the setup program for Excel or Microsoft Office and choose the Change option to install the add-in. After you restart Excel, the add-in should appear in the Add-Ins available box.