If installing the .NET Framework 3.5 on demand or enabling it in
Control Panel fails, you may get one of the following error messages:
•0x800f0906: “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.”
•0x800F081F: “The changes could not be completed. Please reboot your
computer and try again.”
These messages may be displayed for the following reasons:
•Your computer is not connected to the Internet. Please connect, and
then retry the operation.
If you cannot connect to the Internet, you can enable the .NET
Framework 3.5 by using the Deployment Image Servicing and Management
(DISM) command-line tool and specifying the installation media (ISO
image or DVD) you installed Windows 8 from.
1. In Windows 8 or Windows Server 2012, open a Command Prompt window with administrative credentials (that is, choose Run as
2. To install the .NET Framework 3.5 from installation media located in the D:\sources\sxs directory, use the following command:
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess
■/Online targets the operating system you're running (instead of an
offline Windows image).
■/Enable-Feature /FeatureName:NetFx3 specifies that you want to enable
the .NET Framework 3.5.
■/All enables all parent features of the .NET Framework 3.5.
■/LimitAccess prevents DISM from contacting Windows Update.
■/Source specifies the location of the files needed to restore the
feature (in this example, the D:\sources\sxs directory).
For more information about DISM parameters and options, see How to
Enable or Disable Windows Features
•You are using a local source, but the network location is
inaccessible or doesn’t have the right content. Install the .NET
Framework 3.5 from installation media as described in the previous
•Your administrator has configured your computer to use Windows Server
Update Services (WSUS) instead of Windows Update for servicing. Ask
your administrator to enable the policy to use Windows Update instead