ComputerDok – Computer Tips, Windows Guides, & Tech Tutorials

Last updated: September 17, 2026 If Windows 11 or Windows 10 is showing system errors, crashing, freezing, or behaving strangely, corrupted system files may be part of the problem. One of the most useful built-in repair tools for this is SFC / Scannow. SFC stands for System File Checker . It scans protected Windows system files, compares them against a known-good version stored by Windows, and attempts to repair any file that has been damaged, altered, or deleted. This guide explains how to run the SFC command correctly, how to read the scan results, when to bring in DISM, what to do if SFC still cannot repair the files, and which other tools to use when the problem turns out not to be a system-file issue at all. Quick Answer To check and repair Windows system files, open Command Prompt as administrator and run: sfc /scannow Wait until the scan reaches 100% and read the result. If SFC says it found corrupted files but could not repair some of them, run: ...