.Net Framework 3.5 will not install. You get an error 800f081f .
This is due to a bad patch.. or two.
Easily fixed
So In summary , you try to install .Net 3.5 using PowerShell and you get the following error
If you run Get-WindowsFeature it shows Net-Framework-Core removed
If you try to install it via DISM
And DISM error log shows
The reason for this issue is that Microsoft released a bad patch that removed the .Net Framework 3.5 from the image, if it had never been installed….
The problem was:
After you install security update 2966827 or 2966828 there was an issue that prevents the optional Microsoft .NET Framework 3.5 feature from being enabled (
So the solution is to :
Install from https://support.microsoft.com/en-nz/kb/3005628 – Windows8.1-KB2966828-x64.msu that fixes the problem (but does not re-install .net3.5)
Then install the feature with an alternate location, as you have been trying.
e.g.
Install-WindowsFeature –name NET-Framework-Core –source D:\sources\sxs
It should now install the feature successfully