How to fix error 0x800f09 in Windows 10
Windows error 0x800f09 is associated with Microsoft .NET Framework 4.7 for Windows 10. It is one of many Windows errors that can be thrown up by the .NET Framework. As well as generating an error, the installation of the .NET Framework will be stopped. If it forms part of Windows Update or program installation, the overall install will also be stopped.
The Microsoft .NET Framework is a Windows dependency and now cannot be uninstalled. It is a critical component for many games and third-party programs and any issue with it can cause those games and programs to not install or not work. While you cannot uninstall the.NET Framework, you can reinstall it or repair it. Depending on the situation, you can do this as part of a larger update or independently.
What is the Microsoft .NET Framework?
The Microsoft .NET Framework is a series of software APIs. They provide a collection of shared resources that third-party applications can use to interact with Windows. The idea was to provide a coherent library of resources so developers didn’t have to include every dependency in every app download.
Think of it like a school library. You need a book for a term paper question. You take the book, find the answer and return the book. The next student in class takes the book, finds the answer and puts it back. It is the same principle here. Multiple users can use the single resource to get what they need.
The .NET Framework is also a runtime environment. It works similarly to a virtual machine. It functions separately from the host operating system but uses the host’s resources. The idea is to provide a predictable environment for developers to create their programs. An app can be compiled in C++, Visual Basic and a other languages and the .NET Framework could run them all.
These two reasons are why so many programs and games you install will have some kind of .NET Framework component.
Fixing error 0x800f09 in Windows 10
Error 0x800f09 in Windows 10 appears when the installation of the .NET Framework is interrupted or blocked. There are a couple of ways around it.
- The first and easiest is to manually install .NET Framework from here.
- You may also need to install Microsoft Visual C++ x32 version or x64 version.
Download the files above and install them as an administrator. Reboot your computer and retry whatever it was you were trying to do when you saw the error. If the issue was caused by file corruption or missing data, the reinstallation should have addressed it and your process should complete as normal.
If that doesn’t work, there is a specific repair tool for the .NET Framework. Download and run the .NET Framework repair tool from Microsoft. If the tool can fix the issue, it will. Download the tool from the link, right click and select Run as Administrator. Follow the instructions and let the tool do its thing.
If that doesn’t work, we can use DISM to check your Windows installation. As the .NET Framework is now integral to Windows, DISM should check that too.
- Right click the Windows Start button and select Command Prompt (Admin).
- Type ‘DISM /Online /Cleanup-Image /RestoreHealth’ and hit Enter.
- Allow the process to complete.
DISM will check all installed files and repair or replace any that are missing or damaged. If error 0x800f09 is appearing because of either of these, it should be addressed with this.
Error 0x800f09 as part of Windows Update
If you are performing an update and see error 0x800f09, the process is slightly different. We can manually download the KB causing the problem and hopefully circumvent the error.
- Right click the Windows Start button and select Settings.
- Select Update & security and Update History.
- Find the KB code for the one that failed. It will usually be the latest one listed.
- Go to the Windows Catalog site and search for that KB number.
- Select the correct download for your operating system and select Download.
- Install the update manually.
If that doesn’t work we can try the tried and tested method of resetting Windows Update. Follow these steps exactly.
- Right-click the Windows Start button and select Command Prompt (Admin).
- Type ‘net stop wuauserv’ and hit Enter.
- Type ‘net stop cryptSvc’ and hit Enter.
- Type ‘net stop bits’ and hit Enter.
- Type ‘net stop msiserver’ and hit Enter.
- Type ‘Ren C:WindowsSoftwareDistribution SoftwareDistribution.old’ and hit Enter.
- Type ‘Ren C:WindowsSystem32catroot2 Catroot2.old’ and hit Enter.
- Type ‘net start wuauserv’ and hit Enter.
- Type ‘net start cryptSvc’ and hit Enter.
- Type ‘net start bits’ and hit Enter.
- Type ‘net start msiserver’ and hit Enter.
If none of these fixed error 0x800f09, take a look at this page on the Microsoft website. It lists all the reasons a .NET Framework installation may fail and lists a few ways to address them.