If some Windows functions aren't working or Windows crashes, use the System File Checker to scan Windows and restore your files. Though the steps below might look complicated at first glance, just follow them in order, step-by-step, and we’ll try to get you back on track. Run the System File Checker tool (SFC.exe)

The Program Install and Uninstall troubleshooter helps you automatically repair issues when you're blocked from installing or removing programs. It also fixes corrupted registry keys. First, you'll need to download the troubleshooter. Download troubleshooter.

Having trouble connecting to your email from Outlook on your desktop? Follow these steps to let Outlook diagnose and fix errors in your Outlook mail profile that might be causing the issue.

Download the offline installer from your account portal. To download the offline installer, go to www.office.com. If you're not already signed in with the Microsoft account associated with your copy of Microsoft 365 or Microsoft 365 do that now.

System File Checker is a utility in Windows that checks for problems with files on your computer. To run it, follow these steps: Make sure you've installed the latest updates for Windows, and then restart your machine. To find out more, read Update Windows.

If a Microsoft 365 application such as Word or Excel isn’t working correctly, sometimes restarting it will fix the problem. If that doesn’t work, you can try repairing it. When you’re done, you might need to restart your computer. The steps to access the repair tool vary depending on your operating system.

Automatically fix Windows security issues. Follow these steps to automatically diagnose and repair Windows security problems by turning on UAC, DEP protection, Windows Firewall, and other Windows security options and features. Select the Download button on this page.

Describes how to troubleshoot problems that occur when you install, uninstall, or upgrade a program on a Windows-based computer by using Windows Installer.

Sign in to download Microsoft 365 or Office. Go to www.office.com and if you're not already signed in, select Sign in. Note: If you're using Microsoft 365 operated by 21 Vianet, sign in with your work or school account to login.partner.microsoftonline.cn.

This security update resolves a Microsoft Excel remote code execution vulnerability and Microsoft Office information disclosure vulnerability. To learn more about the vulnerabilities, see the following security advisories: Microsoft Common Vulnerabilities and Exposures CVE-2021-31174.