: Ensure your /Source path is exactly where the .cab file is located.

Once you have the file (or have identified its path on your installation media), you must use the tool to install it. You cannot simply "run" a .cab file like an .exe. Step-by-Step Instructions:

: Once you mount the ISO or plug in your USB installer, navigate to: D:\sources\sxs\ (Replace D: with your specific drive letter).

: The progress bar will reach 100%. Once finished, restart your computer to ensure the framework is fully integrated. Troubleshooting Common Errors Error 0x800F081F

:If the file is in your sources\sxs folder on drive D: , type the following:

For further official technical support, you can visit the Microsoft Learn Q&A regarding .NET installation errors.

Avoid downloading .cab files from third-party "driver update" or "DLL download" websites. These files can be tampered with or contain malware.

: Right-click the Start button and select Command Prompt (Admin) or Windows PowerShell (Admin) .