There are several sites regarding this issue, most of them tell you to set a group policy setting to enable the download from Windows Update if you are using a local WSUS server. But I also got an error 0x800f0906 when I set this.

The only solution which has worked yet was to install .Net 3.5 from DVD.

You can do this with the following command (run “cmd” with admin privileges):


 

(Replace “d” with your DVD drive letter)
  [email protected]