Windows 10 Net Framework 3.5 won't install - error 0x080240438

[pers0n]

Was trying to install W7F Diagnostic Tool and I have to have .net framework 3.5 but get this error.

It will download, but once the install begins this error comes up.

 

[AdrianG001]

I had this problem as well on my machine at work.
Try doing the following it worked and allowed me to download
the .Net Framework 3.5 on my Windows 10 azure virtual desktop PC : Go into RegEdit and
set the HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU folder.
DoubleClick on UseWUServer(UseWindowsUpdateServer) and change the value to 0.
If the value is already 0 this fix may not work for you. RESTART afterwards.

 

[Neemobeer]

This usually happens when the feature binary is missing (common in business). Download a Windows 10 ISO and right click iso and select mount.
Assuming it mounts to the D drive open an elevated command prompt and run

DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sources\sxs If it mounts to a different letter change the /Source:D to the appropriate drive letter.

 

[raavan]

Go to control panel and First remove all .net framework

Sent from my Mi A1 using Tapatalk

 

[samK]

Go into RegEdit and
set the HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU folder.
DoubleClick on UseWUServer(UseWindowsUpdateServer) and change the value to 0.