Windows 0x800f081f Error: 7 Proven Ways to Fix CBSESOURCE_MISSING

The 0x800f081f error, also known as CBSESOURCE_MISSING, is a Windows error that usually occurs when Windows cannot find the files it needs to install, repair, or enable a system component.You may encounter this error while installing .NET Framework 3.5, running a DISM repair, installing Windows features, or using Windows Update.

What Causes CBSESOURCE_MISSING?

Several issues can trigger the 0x800f081f error.Common causes include:

  • Missing Windows component files

  • Corrupted Windows system files

  • Damaged Component Store

  • Windows Update problems

  • Incorrect or unavailable DISM repair source

  • Using incompatible Windows installation media

  • Problems installing .NET Framework 3.5

7 Proven Ways to Fix Windows 0x800f081f Error

Try these solutions in order. The first few methods are simple and should be attempted before using installation media.

1. Run the Windows Update Troubleshooter

If the error appeared while installing a Windows update, start with the built-in Windows Update troubleshooter.

On Windows 11:

  • Press Windows + I to open Settings.

  • Select System.

  • Click Troubleshoot.

  • Select Other troubleshooters.

  • Find Windows Update.

  • Click Run.

  • Follow the instructions provided by Windows.

On Windows 10:

  • Open Settings.

  • Select Update & Security.

  • Click Troubleshoot.

  • Select Additional troubleshooters.

  • Choose Windows Update.

  • Click Run the troubleshooter.

2. Run DISM to Repair the Windows Component Store

TextDISM (Deployment Image Servicing and Management) is one of the most useful tools for repairing Windows component problems.Open Command Prompt as Administrator and run:DISM /Online /Cleanup-Image /RestoreHealthPress Enter and wait for the scan to finish.DISM may take several minutes to complete. Do not close the Command Prompt while the operation is running.When it finishes, restart your PC.If DISM reports that source files cannot be foundYou may see another error saying that the source files could not be found. In that situation, you may need to provide Windows with a compatible installation source.

3. Run System File Checker

TextAfter repairing the component store with DISM, run System File Checker (SFC).Open Command Prompt as Administrator and enter:sfc /scannowPress Enter.Windows will scan protected system files and attempt to repair corrupted files.Wait until the scan reaches 100%, then restart your computer.Recommended command orderFor many Windows system-file problems, run:DISM /Online /Cleanup-Image /RestoreHealthfollowed by:sfc /scannowThis combination can repair both the Windows component store and corrupted protected system files.

4. Enable .NET Framework 3.5 Using DISM

If you receive 0x800f081f while installing .NET Framework 3.5, Windows may be unable to locate the required installation files.You can try enabling the feature from an elevated Command Prompt.Run:DISM /Online /Enable-Feature /FeatureName:NetFx3 /AllPress Enter and allow Windows to complete the operation.Restart your computer afterward.If Windows still reports CBSESOURCE_MISSING, continue to the next method.

5. Use Windows Installation Media as the Source

If Windows cannot find the required files locally or through Windows Update, a compatible Windows installation ISO can provide the missing source files.First, mount a Windows installation ISO. Windows will assign it a drive letter, such as D:.Then open Command Prompt as Administrator.For .NET Framework 3.5, you can use:DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /Source:D: ources xs /LimitAccessReplace D: with the actual drive letter of your mounted installation media.ImportantThe Windows installation source should match your installed Windows version as closely as possible.Using an incompatible installation source can result in additional DISM errors.

6. Reset Windows Update Components

A corrupted Windows Update cache can sometimes prevent Windows from obtaining the required component files.Open Command Prompt as Administrator and stop the relevant services:net stop wuauserv
net stop bits
net stop cryptsvc
net stop msiserverThen start them again:net start wuauserv
net start bits
net start cryptsvc
net start msiserverRestart Windows and try the update or feature installation again.If the problem continues, you may need to reset the Windows Update cache more extensively.

7. Perform an In-Place Windows Repair

If you have tried the previous methods and 0x800f081f CBSESOURCE_MISSING still appears, your Windows installation may have damaged or inconsistent system components.An in-place repair installation can be a useful final option.This process reinstalls Windows system components while normally allowing you to keep your personal files and installed applications.Before starting:

  • Back up important files.

  • Make sure you have the correct Windows installation media.

  • Confirm that the installation media matches your Windows version.

  • Follow the Windows setup instructions carefully.

  • Choose the option to keep your personal files and applications when available.