This Error Code 8024400a is commonly caused due to the .NET framework installation failure. These are following ways in which you can attempt to correct this error.
Disclaimers: Before you attempt to fix an issue with the windows update, we highly recommend you to take a registry backup and create a system restore point as a precaution method. In case if something goes wrong, we can restore your computer to the same stage and fix the issues. (In case if you not sure how to back it up, talk to an expert for assistance.)
This .NET Framework 3.5 for Windows 8 or Windows 8.1 won’t come with pre-installed .Windows 8, Windows 8.1 or Windows 10, and must be separately enabled to run applications that depend on it. So enable the .NET Framework 3.5 in Control Panel to avoid Error code 8024400a.
Note: Make sure you have set correct Date and time on your computer, try to install pending updates through other available networks. Run windows update troubleshooter.
If the windows update error code 8024400a still exists, follow some more steps to fix the issue and install/upgrade/update your operating system.
System file scanning process is very simple to try while fixing issues with windows issues. Just follow these steps .
For most of serious issues, and to save your time the best way to fix this critical issues are restoring to good healthy partition. Before doing this stop the windows update services.
Open the command prompt as admin (Mentioned above in sfc scan process), Then instead of running sfc scan now command type this following command in the window.
DISM.exe /Online /Cleanup-image /Restorehealth
After sometime your machine will be restored to good healthy state. Now you can start your windows updates as usual.
Microsoft has released several fix it tools/patches for most of updates issues. Depends on your requirement choose a right fix it tool for your issue and run it on your machine. This will help you when there are simple issues like folder missing errors, permissions related issues.
In this method , we clean and re create the software distribution folder by deleting all temporary files in it.
Follow this when you have less knowledge in windows technology about command prompts, files and registry fixing steps.
During installation you may encounter error 0x800f0906, 0x800f0907, or 0x800f081f, in which case refer to .NET Framework 3.5 installation error: 0x800f0906, 0x800f0907, or 0x800f081f. Note that these are possibly resolved by installing security update 3005628.