Quick Summary
Error 0x800f0906 in Windows typically indicates that the .NET Framework installation or enabling process has failed. This can occur due to missing source files, corruption within the Windows servicing stack, or Group Policy restrictions.
Common Causes
- Missing Source Files: The necessary source files for installing or enabling .NET Framework are not available or accessible by the system. This commonly happens when Windows Update cannot download the required components or when the installation source is corrupted.
- Windows Update Issues: Problems with the Windows Update service, such as corruption in the component store (CBS manifest), can prevent the .NET Framework from being installed correctly. The update service may be failing to retrieve necessary files, or may be encountering errors while processing update requests.
- Group Policy Restrictions: Group Policy settings can sometimes restrict the installation or enabling of optional Windows features, including .NET Framework. These restrictions might be applied either locally on the machine or through a domain policy, preventing the installation process from proceeding.
- Corrupted Component Store: The Component Based Servicing (CBS) store, which holds the files required for installing Windows features, can become corrupted. This corruption can prevent the system from finding and installing the necessary .NET Framework components.
Step-by-Step Fixes
Method 1: Install .NET Framework from Installation Media
Step 1: Mount the Windows installation media (ISO or DVD).
Step 2: Open Command Prompt as an administrator.
Step 3: Use the following command, replacing 'D:' with the drive letter of your installation media: DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /Source:D:\sources\sxs /LimitAccess.
Step 4: If installing .NET Framework 4.8 or later, ensure your system is up-to-date with the latest Windows Updates before attempting to install the .NET Framework.
Method 2: Run System File Checker (SFC) and DISM
Step 1: Open Command Prompt as an administrator.
Step 2: Run the System File Checker: sfc /scannow. Allow it to complete and reboot if necessary.
Step 3: Run DISM to restore the health of the Windows image: DISM /Online /Cleanup-Image /RestoreHealth. This may take some time to complete.
Step 4: Restart your computer after DISM completes and attempt to install or enable .NET Framework again.
Method 3: Check Group Policy Settings
Step 1: Open the Group Policy Editor (gpedit.msc) if you are using a Professional or Enterprise version of Windows. For Home editions, this tool is not available without installing it separately.
Step 2: Navigate to Computer Configuration\Administrative Templates\System.
Step 3: Look for a setting called "Specify settings for optional component installation and component repair". If it is enabled, check if it is preventing the use of Windows Update as a source or specifying an incorrect source path.
Step 4: If the setting is enabled and misconfigured, either disable the setting or correct the source path. Try installing .NET Framework again.
Step 5: If you are on a domain, contact your network administrator to verify domain group policies.
Method 4: Enable .NET Framework using Windows Features
Step 1: Open Control Panel and navigate to "Programs" then "Programs and Features".
Step 2: Click "Turn Windows features on or off".
Step 3: Ensure that ".NET Framework 3.5 (includes .NET 2.0 and 3.0)" or ".NET Framework 4.8 Advanced Services" (or the specific version you need) is checked. If the box is already checked, uncheck it, restart your computer, and then re-check it.
Step 4: Windows may attempt to download necessary files from Windows Update. Ensure you have a stable internet connection.
Step 5: Restart your computer if prompted and check if the error is resolved.