Run Microsoft Defender Offline if: Windows Security (also called Windows Defender Security Center in previous versions of Windows) detects rootkits or other highly persistent malware on your PC and recommends you use Microsoft Defender Offline.

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.

If you can't find an app or program, try the tips in See all your apps in Windows 10 and Program is not listed in add/remove programs after installation. If you get an error message when you're uninstalling, try the Program Install and Uninstall Troubleshooter.

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.

Remove malware from your Windows PC. OneDrive (home or personal) OneDrive for Windows. Microsoft Defender Antivirus is a powerful tool that finds and removes malware from your PC. Here's how to use it in Windows 10 or 11 to scan your PC.

The .NET Framework Repair Tool provides an option to repair the versions of .NET Framework that are installed on the computer (step 3 of the process in the "Repair Tool options" section). The tool requires the redistributable files of those versions to be available at the time of repair.

Virtualization lets your PC emulate a different operating system, like Android™ or Linux. Enabling virtualization gives you access to a larger library of apps to use and install on your PC. If you upgraded from Windows 10 to Windows 11 on your PC, these steps will help you enable virtualization.

Defragment your Windows 10 PC. Windows 10. Optimizing your drives can help your PC run smoother and boot up faster. To optimize them: Select the search bar on the taskbar and enter defrag. Select Defragment and Optimize Drives. Select the disk drive you want to optimize. Select the Optimize button.

To create the installation media, here's what you'll need: A PC with a reliable internet connection. The download time will vary, depending on your internet connection. A USB flash drive, external hard drive, or DVD.

Your PC isn't working well and you recently installed an app. Restore from a system restore point. You suspect your device has been infected. Use installation media to reinstall Windows 11. Select one of the recovery options below and follow the steps to try to get things working again.