====== Installing .NET 3.5 Offline or Manually ======

I recently ran into issues installing SQL 2014 and 2012 which needed .Net 3.5 to complete the install. I was able to install SQL without problems in my personal lab but was unable to complete the installation at work... It turned out that the computers at work were subject to System Center Configuration Manager and as a result couldn't install Windows features without additional steps...

To install .Net 3.5 offline or manually:
  - Insert your Windows Installation Disk into your DVD Drive, mount the ISO, or collect the UNC path to the extracted ISO...
  - Run Command Prompt as Administrator:<code msdos>
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:X:\sources\sxs
</code>
Note : X is the drive letter of DVD drive of the Windows Installation DVD. Change it to point to your Windows Installation ISO location.