DVD DL, Mac OS X 10.11 El Capitan Full OS Install Reinstall Recovery Upgrade These DVDs are NOT original. Installing or upgrading your software from a DVD is NOT a quick process and can take 45-60 minutes to complete. IF, you are getting an error message saying: "The Install OS X Application can't be from this disk. Copy this application to a writable Mac OS Extended formatted disk and reopen it to continue installation ." please do the following steps: Step 1. Insert the dvd into the mac. Step 2. power on your mac holding Command+R to go into the Recovery mode. Step 3: Disconnect your mac from Internet. If you are using wireless go to the right corner of your screen, click on the wireless icon and choose Turn OFF WiFi. Step 4.. Open a Terminal window (Command +N) or go to Utilities/Terminal and type: date 0109200016. Hit Return (Enter) key. Close the Terminal window and click to Reinstall macOS. Step 5. If you still have the error message then reset PRMA/NVRAM: Power off your Mac. Press your Mac's power button and then hold these four keys at the same time: ⌘ + option + P + R. Continue holding the keys until your Mac restarts for the second time. On older Macs, the chime will sound upon restart. Important: During the installation DISCONNECT your Mac machine from Internet. This is the simplest install / upgrade method and the one that you should follow in case you are not sure which is the best option for you. What you see in the pictures is what you will receive! For any issues that you might have during the installation please CONTACT me for assistance ( more than 30 years of experience in MAC system). If you get any error message please access our online free technical support (at the bottom of the installation page that comes with the item). Thank you!