We’ve covered how to enable .NET 3.5.1 on Windows 8 developer preview since then, there are so many changes in Release Preview and RTM version of Windows 8, even in RTM version, it seems Microsoft hasn’t enabled .NET 3.5 by default and you’ll be prompted with Windows Features dialog to install .NET framework 3.5 when you try to run any app that requires .NET 3.5 on your Computer, let us see all three methods of installing .NET 3.5 on Windows 8:online, offline and through Win8 installation media.

app needs .NET 3.5

Installing .NET 3.5 online

If you’ve got Windows Features dialog, click on ”download and install this feature” (the above screenshot taken in RP dialog may be different in RTM which we don’t have access now) which connects to Windows Update site then downloads and installs necessary files on your computer.

.NET 3.5 installed

Enable .NET 3.5 in Control Panel

Open Control Panel> Programs>Programs and Features> Turn Windows Features on or off select .NET framework 3.5 (includes .NET 2.0 and 3.0) and click Ok. Changes will be applied very quickly.

select .NET 3.5 in Windows Features dialog

Adding .NET 3.5 via Win 8 installation media

Insert Windows 8 DVD in DVD drive and open command prompt with  admin privileges and type the following command.

Dism /online /enable-feature /featurename:NetFx3 /All /Source:x:\sources\sxs /LimitAccess

command prompt

I recommend you to follow the second method in Control Panel.