0x800F0906 error on .Net Framework 3.5 installation

Introduction

This resolves an issue when .Net Framework 3.5 refuses to install and provides an error.

Summary

During the manual or ondemand installation of .Net Framework 3.5, the installation hangs or fails providing the error code 0x800F0906 or 0x800F081F.

Error: 0x800F081F
The source files could not be found.
Error: 0x800F0906
The source files could not be downloaded.
Windows couldn't connect to the Internet to download necessary files. Make sure that you're connected to the Internet 
and click "Retry" to try again.

Cause

Three Windows Updates have been known to be a cause for this issue,

  • KB2966826
  • KB2966827
  • KB2966828

Resolution

Method 1: Removing the specific Windows Updates associated with this error.

Open a CMD Prompt with Admistrator Rights,

wusa /uninstall /kb:2966826 /norestart
wusa /uninstall /kb:2966827 /norestart
wusa /uninstall /kb:2966828 /norestart

If you Reboot and attempt an installation of the .Net Framework 3.5 - it should work.

Method 2: Using DISM to install it using Command Prompt

Insert a Windows DVD or Mount an ISO. Open a CMD Prompt with Administrator Rights, run

DISM /Online /Enable-Feature /FeatureName:NetFx3 /All

or

Dism /online /enable-feature /featurename:NetFx3 /All /Source:<drive>:\sources\sxs /LimitAccess

Replace <drive> with a letter of the where the disc is mounted.

Go for a cup of coffee, maybe make a sandwhich - it should say 100% Completed.