The tool removes malicious software from an already-infected computer. Antivirus products block malicious software from running on a computer. It is significantly more desirable to block malicious software from running on a computer than to remove it after infection.

Uninstall or remove apps and programs in Windows. There are different ways to remove apps and programs, so if you can't find the one you're looking for, you can try another location. Note that some apps and programs are built into Windows and can't be uninstalled.

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.

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.

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.

If you trust a file, file type, folder, or a process that Windows Security has detected as malicious, you can stop Windows Security from alerting you or blocking the program by adding the file to the exclusions list.

PC Health Check app brings you up to date info on your Windows device health, helping you take action to improve your device performance and troubleshoot performance problems. It is periodically updated based on customer feedback to help you make the most of your Windows PC. How to open PC Health Check. In Windows, use Search on the taskbar to ...

Microsoft security help and learning. If you suspect that your device may have malware you should have Microsoft Defender run a scan. Here's how to do that on Windows, Mac, or Android.

Microsoft is aware of new variants of the class of attack known as speculative execution side-channel vulnerabilities. The variants are named L1 Terminal Fault (L1TF) and Microarchitectural Data Sampling (MDS). An attacker who can successfully exploit L1TF or MDS may be able to read privileged data across trust boundaries.