To do this, you will need an installation USB flash drive or an ISO image file with your Windows version ( how to check the version of Windows in an ISO image): In this case, you can manually install the NET 3.5 feature from your Windows installation media.
Please reboot your computer and try again Error code: 0x8024402C NET 3.5: Windows couldn’t complete the requested changes. If your computer is not connected to the Internet or disconnected from the network, then an error will appear when installing. Or with PowerShell: Enable-WindowsOptionalFeature -Online -FeatureName "NetFx3".Using DISM: DISM /online /Enable-Feature /FeatureName:"NetFx3".