One of the most useful tools that Windows contain is the System File Checker (SFC) tool, that gives you the ability to check and repair file system files. To run the SFC tool from Windows, you have to open an elevated command and then to type this command: sfc /scannow
The SFC command can run from Windows environment in Normal or in Safe Mode, but some times there is the need to run the SFC command offline, if Windows cannot boot normally or in safe mode. In this case(s), you can boot your system from a Windows Installation Media (DVD or USB) and run the SCF command offline.
In this tutorial you 'll learn how to scan and repair system files by using the System File Checker (SFC) tool, if Windows cannot start. (Windows 10 & Windows 8).
How to run the SFC /SCANNOW command if your system cannot boot to Windows (Offline).
Requirements: In order to run the sfc/scannow in a non bootable Windows system, you need to boot your system from a Windows Installation Media (USB or DVD), according to your Windows OS Version and Edition (e.g. 64 or 32 bit). If you don't have a Windows installation media, then you can create one directly from Microsoft.
1. Boot your computer from the Windows Installation Media.
2. At Language options screen, click Next.
3. Select Repair your computer.
4. Then select Troubleshoot > Advanced Options > Command Prompt.
5. Type BCDEDIT and press Enter.
6. Locate in which drive letter Windows are installed. *
* e.g. As you can see in the screenshot below Windows are installed in drive letter D:
7. At the command prompt window, type the following command to scan and repair system files. *
sfc /scannow /offbootdir=<Windows_Drive_Letter>:\ /offwindir=<Windows_Drive_Letter>:\windows
*Replace the "<Windows_Drive_Letter>" with the drive letter where Windows are installed. **
** e.g. In this example the command should be:
sfc /SCANNOW /OFFBOOTDIR=D:\ /OFFWINDIR=D:\windows
8. Now be patient. The SFC command takes some time to scan and repair the corrupted files. *
* Note: If you receive the "Windows Resource Protection could start the repair service" error message, then make sure that you 're using a Windows Installation Media according to the Windows Version and Edition you try to repair. This means that if you want to repair a Windows 10 64Bit installation, then you have to boot your system from a Windows 10 64bit installation media.
7. When the repair is done, close command prompt window and restart your computer.
That's it! Let me know if this guide has helped you by leaving your comment about your experience. Please like and share this guide to help others.