Cannot install .NET Framework 3.5 on Windows 8When installing MicroStation on Windows 8 operating system, .NET Framework 3.5 fails to install.
In Control Pane l> Programs and Features on the left select Turn Windowsfeature on or off. Enable .NET 3.5. If this method 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 administrator).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/Source:d:\sources\sxsUse /All to enable all parent features of the .NET Framework 3.5.Use /LimitAccess to prevent DISM from contacting Windows Update.Use /Source to specify the location of the files needed to restore the feature.For more information about DISM parameters and options, see How to Enable or Disable Windows FeaturesYou are using a local source, but the network location is inaccessible or does not have the right content. Install the .NET Framework 3.5 from installation media as described in the previous bullet point.Your administrator has configured your computer to use Windows ServerUpdate Services (WSUS) instead of Windows Update for servicing. Ask your administrator to enable the policy to use Windows Update instead of WSUS.If these instructions do not correct the problem, download the paper Microsoft .NET Framework 3.5 Deployment Considerations from the WindowsDev Center for more extensive troubleshooting information.See Also: http://msdn.microsoft.com/library/hh506443(v=VS.110).aspx