Install .Net 3.5 feature into 2012 offline

Your working on a lab and you want to Install .Net 3.5 feature into 2012 offline how do you do it.

If you have ever tried this you will know it works fine in windows server 2008 but in windows server 2012 the .net 3.5 feature install is flakey to say the least and almost always needs a  net connection so that it can see Microsoft’s update servers (or your own WSUS servers) However if your building a quick lab and don’t want to give it net access or a WSUS server how do you get this feature installed?

Open a command prompt with admin rights and enter this one string (change the drive letter to the drive letter the server 2012 disc drive’s)

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

:Note

I had a problem where I followed the above method but got  error code 0x800F0906 and solved it as follows:

Two recent (September 2014) Windows updates refer to .NET Framework 3.5, These installed without the framework being installed? I uninstalled them both and then was able to install .NET Framework 3.5 from Control Panel. I then re applied the updates.

I’m not sure if was necessary to uninstall both updates. They are KB2966826 and KB2966828