SFC or System File Check is a Windows built-in tool in a form of command executing that can be done in command prompt, usually by executing “sfc /scannow” command. It is a very useful tool to scan for missing or corrupted system files, and automatically replace or repair them in Windows 10.
This guide will show you how to run “sfc /scannow” command in Windows 10 in two different conditions:
- If you can boot into Windows and are able to open command prompt
- If you cannot boot into Windows and have to run SFC at boot
How to run SFC /scannow in Windows 10
If you can boot into Windows on your PC and are able to open command prompt without issue, you can run SFC right away in command prompt. Here’s how to do it.
- On Windows 10 search bar, search for “cmd”. Right-click on Command Prompt from the search result and then select “Run as administrator“. Note: You must be an administrator to run the SFC /scannow command.
- In the command prompt window, enter the following command:
- Press Enter key to execute the command. The system file check process may take some time. It will show you if there is any error found and repaired after the scan is completed.
Run SFC /scannow command at boot
If your computer is in serious trouble where it won’t even boot into Windows, here’s how you can run SFC /scannow tool before booting into Windows. There are two methods to force open command prompt (in order to run the “sfc /scannow” command) before booting into Windows.
Method 1: Force boot into Windows Recovery
There is a very handy way to force PC to boot into Windows Recovery without using a Windows 10 installation media.
- Hold and press on the power switch on your computer casing for about 5 seconds until your computer is completely turned off.
- Power it on again.
- As soon as the Windows 10 loading screen shows up, hold and press the power switch again to force another shutdown.
- Repeat this for 3-4 times.
- When Windows 10 detects too many failed startup, it will automatically boot into Windows Recovery on the next restart.
When you are in Windows Recovery, select Troubleshoot > Advanced options > Command Prompt. This will open up a command prompt session right away.
To run SFC, in the command prompt window, enter the following command.
Recommended: Read How to Startup Repair Windows 10 using Command Prompt – a more detailed guide on how to startup repair Windows 10 if you can’t boot into Windows, and more repair commands that you can use in CMD to attempt to fix your issues.
Method 2: Boot from a Windows 10 installation media
Another method to force open command prompt at boot is by using a Windows 10 setup installation media. If you already have the Windows 10 installation media (in the form of DVD or USB), follow the steps in the second part of this method below to force open command prompt during the Windows 10 setup.
If you don’t have a Windows 10 installation media, you can create it using the media creation tool, which can be downloaded from Microsoft. You will have to do this on another computer that is working as you will need access to the internet to download the media creation tool and to create a Windows 10 installation media from it. Here’s how to do it.
- Go to this page. Under “Create Windows 10 installation media”, click on “Download tool now” to download the media creation tool.
- Plug in an empty USB flash drive (or insert an empty DVD if you prefer to burn into DVD instead).
- Run the media creation tool.
- Click to accept the End-user license agreement.
- Next, select Create installation media for another PC.
- Choose the correct settings for your Windows 10 version – language, Windows 10 version, 32 bit or 64 bit.
- When you’re prompted for which media to use, select USB Flash Drive (or DVD if you have a DVD instead).
- Click Next to start create the Windows 10 installation media.
Once you have the Windows 10 installation media ready:
Plug it into your PC. While booting your PC, press F2 key (can be DEL or F12 key, depending on what motherboard you have) to boot into BIOS. In the BIOS interface, look for and set the boot priority or first boot to the USB device (or DVD if your Windows 10 installation media is a DVD). Press F10 to save the settings and restart your PC again.
Your PC should then boot into the Windows 10 setup. While you are at the “Windows 10 setup” screen, press Shift + F10 keys to open up a command prompt session. From there, you can run the System File Check tool by executing “sfc /scannow” command in the command prompt.
How to run SFC /scannow in Safe Mode
If in any case you want to run the SFC /scannow command in Windows 10 safe mode instead, here’s how to force reboot your PC into “safe mode with command prompt”.
- In the start menu, whole holding Shift key, click on Restart.
- Windows will then boot into Windows Recovery Environment screen.
- In the Windows RE screen, select Troubleshoot > Advanced Options > Startup Settings, and then click Restart.
- On the next restart, you will see a screen with several “startup settings”. Press 6 key to boot Windows 10 into “safe mode with command prompt“.
Once you are in safe mode with command prompt, you should then be able to enter and run the “sfc /scannow” command to attempt to fix whatever that is corrupted or missing in the system files.