220-1102 Question 128
Single answersfcA Windows 10 user reports that several built-in apps are crashing and some system functions stop responding after a recent improper shutdown. You suspect corrupted protected system files, but the PC still boots normally to the desktop. Which command should a technician run first to verify and repair Windows protected system files from within the running operating system?
- A
sfc /scannow
- B
chkdsk /r
- C
bootrec /fixmbr
- D
format c:
Show answer and explanation
Correct answer: A
Explanation
When a Windows system is bootable but shows signs of corrupted protected operating system files, CompTIA A+ expects technicians to recognize System File Checker as a standard troubleshooting tool. Running 'sfc /scannow' from an elevated Command Prompt scans integrity-protected files and replaces incorrect versions when possible. This aligns with Microsoft guidance for repairing missing or corrupted system files in a running Windows installation. If SFC cannot complete the repair because the component store is damaged, a common next step in real-world support is to use DISM with commands such as 'DISM /Online /Cleanup-Image /RestoreHealth' before running SFC again. In this question, however, the best first action specifically related to SFC is 'sfc /scannow'.
- A. Correct.
Correct. The System File Checker command 'sfc /scannow' scans all protected Windows system files and attempts to repair corrupted versions using the local component store. This is the appropriate first step when Windows is still able to boot and symptoms suggest damaged system files.
- B. Incorrect.
Incorrect. 'chkdsk /r' checks the disk for file system errors and locates bad sectors, which is useful for storage-related issues. However, it does not specifically verify or repair protected Windows system files, so it is not the best first command for this scenario.
- C. Incorrect.
Incorrect. 'bootrec /fixmbr' is used in Windows Recovery Environment to repair certain boot-related problems, such as a damaged master boot record. In this scenario, the system already boots to the desktop, so a boot repair command is not the appropriate first choice.
- D. Incorrect.
Incorrect. 'format c:' would erase the contents of the system drive and is a destructive action, not a troubleshooting step for repairing corrupted Windows system files. Someone might pick it by confusing repair with reinstallation, but it is not appropriate here.