How to Fix Error 0x800F0950 .NET Framework 3.5 Installation

The error code 0x800F0950 appears on Windows 10 and Windows 11 when trying to install the .NET 3.5 Framework using the conventional installer or when trying to launch a game or app that requires this dependency. The error message accompanying the error code is ‘The following feature couldn’t be installed’.

NET Framework 3.5 Error

After investigating this issue thoroughly and attempting to replicate the issue on both Windows 10 and Windows 11 machines, it turns out that there are several different scenarios that are likely responsible for the 0x800F0950. Here’s a shortlist of causes that are likely to facilitate the apparition of this issue:

  • Missing 3.5 .NET Framework – If you’re seeing this error while attempting to launch a program that requires this dependency on Windows 10, all you need to do is trigger the installation from the Windows Features screen. This will end up bypassing any issues that you might be currently having with Windows Installer.
  • Missing 4.8 .NET Framework – In case you’re dealing with this problem after you updated to Windows 11, the error is probably occurring because your OS doesn’t have the latest .NET framework package. Even though the error points towards the .NET 3.5 iteration, you actually need to ensure that you have installed the latest version using the official channels.
  • Remnants from a previous .NET Framework installation – As it turns out, if you previously dealt with a botched .NET installation or you tried to uninstall a Framework package but got interrupted, you might see this error because the installer is prevented from installing new files due to remnant corrupted equivalents. In this case, you can fix the issue by running the .NET Framework Repair Tool.
  • Outdated Windows build – Another underlying reason that might trigger the installation of the .NET framework to fail is an outdated OS build. It’s not uncommon (on both Windows 10 and 11) for the installation to fail because the .NET Framework the user is trying to install is not supported on the OS build. If you find yourself in this scenario, you can get the issue resolved by installing every pending Windows update first before trying the .NET framework installation.
  • .NET Framework is waiting to be installed via WU – According to some affected users, you can also expect to see this issue occurring in a scenario where the same .NET Framework package that you are trying to install is already downloaded and waiting to be installed via WU. In this case, installing every pending update and rebooting your PC should fix the issue automatically.
  • Corrupted Windows Installer component – If you are unable to install the .NET framework because you are dealing with a corrupted Windows Installer component, one way to bypass the issue completely is to handle the installation from a compatible Windows 10 or Windows 11 installation media via DISM. If the DISM component is also affected, you can also create a custom Installation script and running from an elevated CMD prompt.
  • System File Corruption – If you end up trying out every possible way to bypass the error code and complete the installation of the pending .NET framework and nothing works, the only viable alternative left to you is to perform a repair install in order to refresh every corrupted Windows component.

Now that you are familiar with every potential scenario that might cause this issue, here’s a list of possible fixes that other affected users have successfully used to get to the bottom of this error code:

Install .NET Framework 4.8 from DotNET (Windows 11 Only)

Keep in mind that Windows 11 is known to trigger the 0x800F0950error when users attempt to launch a game (via Steam or other game launchers) that require .NET Framework version 3.5. The trick with Windows 11 is, you no longer only need the required version to launch the game – You also need every newer iteration in order to be able to run the game.

If you find yourself in this particular scenario, you should be able to get the issue fixed by accessing the DotNET homepage and downloading the Runtime version of the 4.8 .NET Framework using the official server.

Follow the step by step instructions below to learn how to do this:

  1. Open any browser and access the download page of DotNET Framework 4.8.
  2. Once you’re inside, click on the Download .NET Framework 4.8 Runtime button.
    Downloading .NET Framework 4.8
  3. After the download is complete, double-click on the executable that you’ve just downloaded and accept the UAC (User Account Control) prompt.
  4. Inside the installation window, follow the remaining instructions to complete the installation of .NET Framework 4.8.
  5. Once the operation is complete, reboot your computer and see if the issue is now fixed.

In case the same 0x800F0950 error is still occurring, move down to the next potential fix below.

Running the .NET Framework Repair Tool

If your previous attempts at installing a .NET Framework version got interrupted by an unexpected shutdown or anything similar, it’s possible that you’re dealing with some kind of remnant files that are affecting the installation of new .NET framework instances.

In case you find yourself in this situation, the best course of action is to run the Microsoft .NET Framework Repair Tool and apply the recommended fix in order to clear the remnant files and data clusters that might be responsible for the apparition of the 0x800F0950.

Update: This tool will work on both Windows 10 and Windows 11. The instructions are virtually the same.

Follow the instructions below to download and run the .NET Framework Repair Tool:

  1. Open up the download page of the Microsoft .NET Framework Repair tool from any browser.
  2. Once you’re inside the correct page, click on the Download button under Microsoft .NET Framework Repair Tool.
    Downloading the latest version of the .NET repair tool
  3. After the download is complete, double-click on NetFxRepairTool and click yes at the User Account Control to grant administrative privileges.
  4. Follow the on-screen instructions to deploy the repair utility, then follow through with the recommended repair strategies once the initial scan is complete.
    Deploy the recommended changes
  5. After the recommended repair strategies are enforced, reboot your computer one more time and retry the installation of the .NET framework again after the next startup is complete.

If the same kind of problem is still occurring, move down to the next potential fix below.

Install .NET Framework 3.5 using Windows Features (Windows 10 Only)

If you’re seeing this error when trying to install the .NET Framework version 3.5 from an installer you’ve downloaded with your browser, you might be able to circumvent the problem entirely by installing it via the Windows Features menu.

Note: Windows 11 already has a newer version of this framework installed and enabled by default, so no action is required on your part to ensure it’s available to the apps that need it.

Keep in mind that Windows 10 already includes an archive of .NET Framework version 3.5, you just have to prompt it to install. Several affected users that were previously encountering the error code 0x800F0950 when installing .NET Framework version 3.5 conventionally have confirmed that the installation went smoothly when they tried to do it via the Windows features screen.

To install the .NET Framework 3.5 via the Windows Features screen, follow the instructions below:

  1. Open up a Run dialog box by pressing Windows key + R. Next, type ‘appwiz.cpl’ inside the text box and press Enter to open up the Programs and Features menu.
    Type appwiz.cpl and Press Enter to Open Installed Programs List
  2. Once you’re inside the Programs and Features menu, use the menu on the right to click on Turn Windows features on or off.
    Accessing the Windows features menu
  3. When you’re inside the Windows features screen, start by checking the box associated with .NET Framework 3.5 (this package includes .NET 2.0 and 3.0), then click Ok to save the changes.
    Enabling the .NET Framework 3.5
  4. At the confirmation prompt, click Yes to initiate the procedure, then wait for the package to be successfully installed.
  5. Once the operation is complete, reboot your computer and see if the problem is fixed once the next startup is complete.

In case this method was not applicable, you encountered a different error, or you’re planning on installing the .NET Framework 3.5 package from an executable you previously downloaded, move down to the next potential fix.

Install every Pending Windows Update

One reason that might trigger the 0x800F0950error when you’re attempting to install the .NET Framework 3.5 update is the fact that Windows Update already has a scheduled update ready to do the same thing.

Some users encountering the same error code have reported that they finally managed to fix the issue after they updated their Windows 10 / 11 version to the latest build available. After doing this and restarting their computer, most have reported that .NET Framework 3.5 was already installed so there was no need to use the dedicated installer.

Note: The instructions on installing any pending updates are identical on both Windows versions.

If this scenario is applicable,  install every pending update for your Windows 10 computer and see if this takes care of the issue automatically:

  1. Open up a Run dialog box by pressing Windows key + R. Next, type ‘ms-settings:windowsupdate’ inside the text box and press Enter to open up the Windows Update tab of the Settings app.
    Run dialog: ms-settings:windowsupdate
  2. Inside the Windows Update screen, move over to the right-hand section and click on Check for Updates.
    Installing every pending Windows update
  3. Next, follow the on-screen instructions to install each pending update until you bring your computer up to date.
    Note: In case you are prompted to restart before you get the chance to install every pending update, restart as instructed. But once the next startup is complete, return to the same Windows Update screen to complete the installation of the remaining updates.
  4. Once you finally manage to install every pending Windows update, you should find that the .NET Framework 3.5 was already installed by the Windows Update component.

If this didn’t happen or you are not prepared to install the Windows Updates that are currently pending, move down to the next potential fix below.

Installing NET Framework via Installation Media

In case the first two fixes didn’t work for you, one viable fix that a lot of users have used successfully is to force a compatible installation media to install the NET Framework for you from an elevated Command Prompt or Powershell window.

This is the equivalent of the method below, but it’s way quicker if you already have a compatible installation media.

In case you want to give this method a try, follow the instructions below to install the .NET Framework 3.5 version directly from a compatible installation media:

Note: You can follow the instructions below on both Windows 10 and Windows 11. Just make sure you insert a compatible installation media.

  1. Insert the compatible installation media in your DVD drive, flash drive, or mount it in case you are using an ISO.
  2. Press Windows key + R to open up a Run dialog box. Next, type ‘cmd’ inside the text box and press Ctrl + Shift + Enter to open up an elevated Command Prompt. When you see the UAC (User Account Prompt), click Yes to grant administrative privileges.
    Type “cmd” into the Run dialog

    Note: If you want to use Powershell, type ‘PowerShell‘ instead of ‘cmd‘.

  3. Once you’re inside the elevated CMD prompt, type the following command and change ‘XXX‘ with the letter that is currently holding the installation media:
    Dism /online /enable-feature /featurename:NetFX3 /All /Source:XXX:\sources\sxs /LimitAccess
  4. Press Enter to initiate this process, then wait for the operation to complete. Once the installation is complete, restart your computer and see if the NET framework was installed successfully once the next startup is complete.

In case you still end up seeing the 0x800F0950 error or the installation failed with a different error code, move down to the next potential fix below.

Creating a Custom Installation Script (Windows 10 Only)

If the method above didn’t work for you or you are looking for an alternative to using Windows Features, you should be able to bypass the 0x800F0950 error by creating a custom CMD installation script and run it with elevated privileges.

But keep in mind that in order to do this, you will need to create a compatible installation media for your Windows 10 computer.

Update: This method will not work on Windows 11.

If you already have a compatible installation media or you just created one using the guide above, follow the instructions below to force the installation of the .NET Framework 3.5 using a custom script:

  1. Open up a Run dialog box by pressing Windows key + R. Next, type ”notepad.exe” and press Ctrl + Shift + Enter to open up an elevated Notepad window.
    Opening an elevated Notepad window

    Note: When you’re prompted by the UAC (User Account Control), click Yes to grant administrative privileges.

  2. Once you’re inside the elevated Notepad window, paste the following code:
    @echo off 
    Title .NET Framework 3.5 Offline Installer 
    for %%I in (D E F G H I J K L M N O P Q R S T U V W X Y Z) do if exist "%%I:\\sources\install.wim" set setupdrv=%%I 
    if defined setupdrv ( 
    echo Found drive %setupdrv% 
    echo Installing .NET Framework 3.5... 
    Dism /online /enable-feature /featurename:NetFX3 /All /Source:PLACEHOLDER:\sources\sxs /LimitAccess 
    echo. 
    echo .NET Framework 3.5 should be installed 
    echo. 
    ) else ( 
    echo No installation media found! 
    echo Insert DVD or USB flash drive and run this file once again. 
    echo. 
    ) 
    pause
    
    

    Note: You will need to replace PLACEHOLDER with the letter of the drive that’s currently hosting the installation media.

  3. Once you successfully insert the code and you modify it accordingly, use the ribbon at the top to select File > Save As then select an appropriate location where you want to save the script you’ve just created.
  4. You can name it however you want, but it’s IMPORTANT to end the name with the ‘.cmd’ extension. After you add the correct extension, click on the Save button to create the fix.
    Creating the CMD fix
  5. Next, navigate to the location where you saved the .cmd script previously, then right-click on the file and click on Run as administrator from the newly appeared context menu. Next, click Yes at the confirmation prompt and wait for the operation to complete.
  6. At the end of this procedure, this custom script will install the .NET 3.5 Framework and use the Windows installation media to access any support files to get the job done. Once this operation is complete, restart your computer and see if the problem is now fixed.

If you’re still seeing the 0x800F0950 error code or you’re stuck with a different error code, move down the next potential fix below.

Performing a Repair Install

If none of the potential fixes above have worked for you, it’s likely that you’re dealing with some type of corruption that will not go away conventionally. In this case, you should try to resolve the 0x800F0950 error code by resetting every Windows-related file.

You can do this with a clean install, but our recommendation is to go for a repair install (in-place repair) instead.

While a clean install will not discriminate and delete everything on your OS drive (unless you back it up in advance), a repair install will only touch OS components, leaving personal files, apps, and games intact.

Kevin Arrows
Kevin is a dynamic and self-motivated information technology professional, with a Thorough knowledge of all facets pertaining to network infrastructure design, implementation and administration. Superior record of delivering simultaneous large-scale mission critical projects on time and under budget.

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How to Fix Error 0x800F0950 .NET Framework 3.5 Installation

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