Software & Apps Windows Scan and Fix Your Hard Drive: Windows System Files Share Pin Email Print krisanapong detraphiphat / Getty Images Windows The Ultimate Laptop Buying Guide By Mark Baggesen Writer Mark Baggesen is a former Lifewire writer who has 20+ years' experience and has in web development, communications, web analytics, and databases. our editorial process LinkedIn Mark Baggesen Updated December 23, 2019 70 70 people found this article helpful All activities, including applications such as word processors, email clients, and internet browsers are controlled by system program files. Over time, the files can be changed or corrupted by new software installations, viruses or problems with the hard drive. Scanning and fixing Windows system files improves the function and speed of your computer. Instructions in this article apply to Windows 10, Windows 8, Windows 7, and Windows Vista. 01 of 04 Why Run System File Checker The more corrupt the system files are, the more unstable and problematic your Windows operating system will become. Windows may crash or behave differently than you expect. That is why scanning and fixing Windows system files is so important. System File Checker program scans all protected system files and replaces corrupted or incorrect versions with correct Microsoft versions. This procedure can be beneficial, especially if your computer has been displaying error messages or running erratically. 02 of 04 Running System File Checker in Windows 10, 7, and Vista To use the System File Checker in Windows 10, Windows 7 or Windows Vista, follow these steps: Close any open programs on your desktop.Select the Start buttonType Command Prompt in the Search box.Select Run as administer.Enter an administrator password if requested to do so or select Allow.At the Command Prompt, enter SFC /SCANNOW.Press Enter to begin the scan of all protected system files. Do not close the Command Prompt window until the scan is 100 percent complete. 03 of 04 Running System File Checker in Windows 8 and 8.1 To use the System File Check program in Windows 8 or Windows 8.1, follow these steps: Close any open programs on your desktop. Point to the lower right corner of the screen and select Search or swipe from the right edge of the screen and select Search.Type Command Prompt in the Search box.Right-click Command Prompt and select Run as administrator.Enter an administrator password if requested to do so or select Allow.At the Command Prompt, enter SFC /SCANNOW.Select Enter to begin the scan of all protected system files. Do not close the Command Prompt window until the scan is 100 percent complete. 04 of 04 Allow System File Checker to Work It may take from 30 minutes to a couple of hours for the System File Checker to scan and fix all the Windows system files. It works fastest if you do not use the computer during this process. If you continue to use the PC, performance will be slow. When the scan is complete, you will likely receive one of the following messages: Windows Resource Protection did not find any integrity violations. Your computer was not missing any files or have any corrupted system files.Windows Resource Protection found corrupt files and successfully repaired them. Windows Resource Protection could not perform the requested operation. Restart your computer in safe mode and confirm that the PendingRenames and Pending Deletes folders are under %WinDir%\WinSxS\TempWindows Resource Protection found corrupt files but was unable to fix some of them. Corrupted files must be repaired manually.