Download the .msu or .exe file for your version of Windows. "x86" means that you have a 32-bit version of Windows. "x64" means that you have a 64-bit version of Windows. If you are not sure about which operating system you have, download and install the x64-based version.

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.

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.

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.

The Microsoft Defender Offline scan will automatically detect and remove or quarantine malware. Learn how to remove malware from your PC. Use Microsoft Defender Antivirus in Windows 10 or Windows 11 to scan your PC for malware, viruses, or other threats.

Use the 32-bit installer if you’re using a 32-bit version of Windows and the 64-bit installer with a 64-bit version of Windows. To determine which version of Windows you’re using, follow the steps in Method 1 or 2. If one method doesn’t work, try the other.

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

You can start a scan for malware any time you like. Note: Microsoft Defender currently offers anti-malware on Windows, Android, and macOS. Windows Android Mac. From the Microsoft Defender dashboard. Select Device details.

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.