Commvault Simpana 10 Software Install Failure

AKA: How to install .NET 3.5 on Windows Server 2012.

Yesterday, the installation of the Commvault File System and MSSQL Server agents failed on a new Windows Server 2012 VM.   I turns out, the agents require .Net 3.5 and the 3.0 and 2.0 package. 

I went to install the Feature and received the following warning:

"One or more installation elections are missing source files on destinati..."

The .Net 3.5 install files are not loaded by default. To resolve this issue, attach the Windows 2012 install media to the VM and run the following command in Powershell with elevated rights (substitute in the appropriate cd-rom drive letter):

dism.exe /online /enable-feature /all /featurename:NetFX3 /Source:X:\sources\sxs /LimitAccess

After the install completes, disconnect the cd rom from the VM and restart the server:

I reran the agent install and it completed successfully: