Integration and Slipstream mean basically the same. It means you can integrate these with dism Reverse Integration is another word for Sysprep. You do a regular install of your OS, but when you get to the OOBE part where you enter a username, you press Shift+Ctrl+F3 and you will be logged in to (the aministrator account in) audit mode... Here you install your apps like .net 4.5.1, updates that cannot be integrated/slipstreamed like WMF 4.0, Servicing Stack update, etc. After you finish with audit mode, you generalize and shutdown your work, then you boot from another source and use dism to capture a image of the install you just made. This will give you a new install.wim with .net and other stuff you did during your audit mode session