I have found that I am unable to install .NET framework 3.5 after patching windows 2012 R2 The initial install of Windows 2012 R2 shows the Feature ".NET 3.5 Framework Features" as having a status of "Removed". It is initially possible to install this feature as long at the original install media is in the DVD Drive. See http://technet.microsoft.com/en-ca/library/dn482071.aspx and http://support.microsoft.com/kb/2734782 While this works on the intial install, I have found that after you have patched a server, using Windows Update, you can no longer install the feature. I have not found a work-around yet.
