Running SFC and DISM to Repair Windows System Files

Corrupted system files cause a wide range of Windows issues. The System File Checker (SFC) and DISM tools can detect and repair them. Always run these from an elevated (Administrator) command prompt. First run DISM to repair the Windows component store: 'DISM /Online /Cleanup-Image /RestoreHealth'. This requires internet access to download replacement files from Windows Update and takes 5-15 minutes. Once complete, run SFC: 'sfc /scannow'. SFC will scan all protected system files and replace corrupted ones from the DISM-repaired store. After both tools complete, review the CBS.log file at C:\Windows\Logs\CBS\CBS.log for details. Search for '[SR]' entries to see what SFC found and fixed. Reboot after repairs. If SFC continues to find unfixable errors, the Windows image itself may need to be reset or reinstalled.