How to Fix Sfc_os.dll Not Found or Missing Errors

A Troubleshooting Guide

Screenshot of an sfc_os DLL error message in Windows
Sfc_os.dll Error Message.

Sfc_os.dll errors are caused by situations that lead to the removal or corruption of the sfc_os DLL file.

In some cases, sfc_os.dll errors could indicate a registry problem, a virus or malware issue, or even a hardware failure.

There are several different ways that sfc_os.dll errors can show up on your computer. Here are some of the more common ways that you might see sfc_os.dll errors:

Sfc_os.dll Not Found
This application failed to start because sfc_os.dll was not found. Re-installing the application may fix this problem.
Cannot find [PATH]\sfc_os.dll
The file sfc_os.dll is missing.
Cannot start [APPLICATION]. A required component is missing: sfc_os.dll. Please install [APPLICATION] again.

The context of the sfc_os.dll error is an important piece of information that will be helpful while solving the problem.

Sfc_os.dll error messages might appear while using or installing certain programs, when Windows starts or shuts down, or maybe even during a Windows installation.

The sfc_os.dll error message could apply to any program or system that might utilize the file on any of Microsoft's operating systems including  Windows 10Windows 8Windows 7Windows VistaWindows XP, and Windows 2000.

How to Fix Sfc_os.dll Errors

Important: Do not download sfc_os.dll from a "DLL download" website. There are many reasons why downloading a DLL file is a bad idea. If you need a copy of sfc_os.dll, it's best to obtain it from its original, legitimate source.

Note: Start Windows in Safe Mode to complete any of the following steps if you're unable to access Windows normally due to the sfc_os.dll error.

  1. Restore sfc_os.dll from the Recycle Bin. The easiest possible cause of a "missing" sfc_os.dll file is that you've mistakenly deleted it.
    1. If you suspect that you've accidentally deleted sfc_os.dll but you've already emptied the Recycle Bin, you may be able to recover sfc_os.dll with a free file recovery program.
    2. Important: Recovering a deleted copy of sfc_os.dll with a file recovery program is a smart idea only if you're confident you've deleted the file yourself and that it was working properly before you did that.
  2. Run a virus/malware scan of your entire system. Some sfc_os.dll errors could be related to a virus or other malware infection on your computer that has damaged the DLL file. It's even possible that the sfc_os.dll error you're seeing is related to a hostile program that's masquerading as the file.
  3. Use System Restore to undo recent system changes. If you suspect that the sfc_os.dll error was caused by a change made to an important file or configuration, a System Restore could solve the problem.
  1. Run the sfc /scannow System File Checker command to replace a missing or corrupt copy of the sfc_os.dll file. Since this DLL file is provided by Microsoft, the System File Checker tool should restore it.
  2. Copy the sfc_os.dll file from a Windows installation disc. If the sfc command didn't replace the sfc_os.dll file, you can grab a fresh copy from the install disc that corresponds to your version of Windows.
    1. One way you can do this is by popping in the Windows disc or opening the ISO equivalent, and then, depending on the version of Windows on that disc, open \sources\install.wim or \sources\install.esd with 7-Zip, and navigate to the proper folder that corresponds to your specific edition of that Windows version (e.g. Windows 7 Professional, Windows 10 Home, etc.). You can figure out which number belongs to which edition by inspecting the [1].xml file located on the disc (search for all the image index entries).
    2. Then, once you're viewing the original install files for that particular version of Windows, copy the sfc_os.dll file from the \Windows\System32\ folder or the \Windows\SysWOW64\ folder, depending on the sfc_os.dll file that's missing. Paste it into the corresponding folder on your computer where the DLL file is missing (System32 or SysWOW64).
    3. Important: Be sure to use the same Windows disc that corresponds to your Windows version. For example, use a Windows 7 disc if you're seeing this DLL error in Windows 7, a Windows 10 disc for a Windows 10 sfc_os.dll error, etc. If you're using Windows XP, follow these steps instead, and replace the "i386" command with "amd64" if the one described on that page doesn't work.
    4. Note: Try your best to complete this step. Getting sfc_os.dll from the original source is the best way to fix any missing sfc_os.dll errors.
  1. Reinstall the program that uses the sfc_os.dll file. If the sfc_os.dll DLL error occurs when you use a particular program, reinstalling the program should replace the file.
  2. Update the drivers for hardware devices that might be related to sfc_os.dll. If, for example, you're receiving a "The file sfc_os.dll is missing" error when you play a 3D video game, try updating the drivers for your video card.
    1. Note: The sfc_os.dll file may or may not be related to video cards - this was just an example. The key here is to pay very close attention to the context of the error and troubleshoot accordingly.
  3. Roll back a driver to a previously installed version if sfc_os.dll errors began after updating a particular hardware device's driver.
  4. Install any available Windows updates. Many service packs and other patches replace or update some of the hundreds of Microsoft distributed DLL files on your computer. The sfc_os.dll file could be included in one of those updates.
  5. Test your memory and then test your hard drive. We​'ve left the majority of hardware troubleshooting to the last step, but your computer's memory and hard drive are easy to test and are the most likely components that might cause sfc_os.dll errors as they fail.
    1. If the hardware fails any of your tests, replace the memory or replace the hard drive as soon as possible.
  1. Repair your installation of Windows. If the individual sfc_os.dll file troubleshooting advice above is unsuccessful, performing a startup repair or repair installation should restore all Windows DLL files to their working versions.
  2. Use a free registry cleaner to repair sfc_os.dll related issues in the registry. A free registry cleaner program may be able to help by removing invalid sfc_os.dll registry entries that might be causing the DLL error.
    1. Important: We rarely recommend the use of registry cleaners. We've included the option here as a "last resort" attempt before the destructive step coming up next.
  3. Perform a clean installation of Windows. A clean install of Windows will erase everything from the hard drive and install a fresh copy of Windows. If none of the steps above correct the sfc_os.dll error, this should be your next course of action.
    1. Important: All the information on your hard drive will be erased during a clean install. Make sure you've made the best attempt possible to fix the sfc_os.dll error using a troubleshooting step prior to this one.
  1. Troubleshoot for a hardware problem if any sfc_os.dll errors persist. After a clean install of Windows, your DLL problem can only be hardware related.