To get the latest features and maintain the security, stability, compatibility, and performance of your Mac, it's important to keep your software up to date. Apple recommends that you always use the latest macOS that is compatible with your Mac.

• El Capitan Reinstall

El Capitan disk has an embbed security certificate that has expired in 2016. Just change your system date, let's say to, install El Capitan, then change the date back to today. Was this answer helpful? As explained here, OS X 10.11 'El Capitan' fails to install because it is too old (the technical reason being that the signing certificate is no longer valid). But you can trick the OS X installer into thinking that it is 2017 and it will happily run without any errors.

I have a new 480 gig SSD from OWC I just replaced because the company thought it was a drive problem and sent me a new one, trying to install with an El Capitan USB it will get to 1about a sec on the install, then after 10 min or so will say it failed and to try again later, on rebooting my drive is gone from the machine/disk utility. I cannot use the package installer from the download provided by Apple to create the installer App for El Capitan. However, I need access to the installer so that I’m able to use the createinstallmedia command. If the drive is newish and you don't suspect it's failing, reinstall Snow Leopard (if you have the DVD that came with the MB) and update it to 10.6.8 once the install is done - that should get you to the version of the AppStore that will get you to the El Cap download. Re-download the El Capitan installer again and once you have it, build a.

Learn how to upgrade to macOS Big Sur, the latest version of macOS.

Check compatibility

The version of macOS that came with your Mac is the earliest version it can use. For example, if your Mac came with macOS Big Sur, it will not accept installation of macOS Catalina or earlier.

If a macOS can't be used on your Mac, the App Store or installer will let you know. For example, it might say that it's not compatible with this device or is too old to be opened on this version of macOS. To confirm compatibility before downloading, check the minimum hardware requirements:

• macOS Catalina 10.15 hardware requirements
• macOS Mojave 10.14 hardware requirements
• macOS High Sierra 10.13 hardware requirements
• macOS Sierra 10.12 hardware requirements
• OS X El Capitan 10.11 hardware requirements
• OS X Yosemite 10.10 hardware requirements

Download macOS using Safari on your Mac

Safari uses these links to find the old installers in the App Store. After downloading from the App Store, the installer opens automatically.

• macOS Catalina 10.15 can upgrade Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks
• macOS Mojave 10.14 can upgrade High Sierra, Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion
• macOS High Sierra 10.13 can upgrade Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion

Safari downloads the following older installers as a disk image named InstallOS.dmg or InstallMacOSX.dmg. Open the disk image, then open the .pkg installer inside the disk image. It installs an app named Install [Version Name]. Open that app from your Applications folder to begin installing the operating system.

El Capitan Reinstall

• macOS Sierra 10.12 can upgrade El Capitan, Yosemite, Mavericks, Mountain Lion, or Lion
• OS X El Capitan 10.11 can upgrade Yosemite, Mavericks, Mountain Lion, Lion, or Snow Leopard
• OS X Yosemite 10.10can upgrade Mavericks, Mountain Lion, Lion, or Snow Leopard