The other day a co-worker needed to borrow a Mac, so I grabbed an older MacBook Air from storage. I decided to wipe out the laptop’s flash storage and install a fresh version of OS X. I created a bootable USB flash drive installer, plugged it into the laptop, pressed the Option key as the machine booted, and then selected the USB drive as the boot disk.
Here’s how to securely delete all of your files, then install a fresh version of macOS. If you’re selling or giving away your computer, this is the only way to make sure whoever ends up with your Mac can’t access to your files, and won’t have to deal with any modifications you’ve made to macOS over the years. After the download is done, it will install the fresh version of the the macOS operating system and you can carry on with the set-up. Install macOS Using a USB Bootable Drive. Using a USB Bootable Drive to reinstall macOS is very handy as you don’t have to download the entire macOS operating system again.
I then ran Disk Utility to reformat the drive and then ran the installer to install OS X. It looked like things were moving along, until this appeared on the screen.
I created another boot disk using a different storage drive, in case it was a hardware problem, but I got the same error. Nodame cantabile drama episode 1. I figured that the fact that the laptop had been in storage for a while had something to do with it, and it did.
Note: This fix should work with OS X Mavericks and El Capitan. It also worked for me with macOS Sierra, which shows a different error message (“The installer payload failed signature check” pops up near the end of the installation) than the one that appears for El Capitan and Mavericks.
How to fix the problem
The installer checks the date on the computer. If the date isn’t current, you get the error above. The fix involves correcting the date on your Mac.
If you have an older OS on the Mac
If you have a complete OS on the Mac already, boot into it. Fix the date in the Date & Time system preference (Apple menu > System Preferences). Reboot using the USB boot disk, and you should be able to proceed with the installation.
If you don’t have an OS on the Mac
If you are in a situation like I was, and you don’t have a complete OS on your disk (you reformatted it), you’ll find that there’s no way to access the Date & Time system preference when you use an external USB boot installer drive. The Apple menu doesn’t give you access to System Preferences. You have to use the Terminal to set the date and time.
If you use an external boot disk, you Mac starts up into OS X Disk Utilities. You can access the Terminal by clicking on the Utilities menu and selecting Terminal. Once the Terminal has launched, follow these steps.
- At the prompt, type
dateto see the date that’s on the Mac. For example, here’s the date of the MacBook Air I worked on.
- If your Mac is connected to the internet, you can tell your Mac to check online for the current date and time. You can do this by typing at the prompt
ntpdate -u time.apple.comand then pressing Return.
Your Mac should now have the current date and time. If you enter date again (as I did in the screenshot above) the information that appears will be current. You can now run the OS installer.
If you don’t have an internet connection
You can still use Terminal to set the date. Go into the Terminal as described above, then follow these steps.
- At the prompt, type
dateto see the date that’s on the Mac. - Figure out the numerical representation of the date and time. The pattern you need to follow:
- Month: in two-digit format. For example, July is 07.
- Day: in two-digit format. For example, the 19th is 19. Another example: the 7th is 07.
- Time: in military format of hours and minutes. For example, 2:00 p.m. is 1400.
- Year: Last two digits.
In my example, the numerical representation is 0719140016. This stands for July (07) 19, (19), 2 p.m. (1400), 2016 (16).
- At the prompt, type
date [numerical], with[numerical]being the representation you figured out. In my example, I typeddate 0719140016. Then press Return.
The date should be set. You can check the date again by typing date at the prompt. You can now run the installer.
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.
Learn how to upgrade to macOS Big Sur, the latest version of macOS.
Check compatibility
If a macOS installer can't be used on your Mac, the installer will let you know. For example, it might say that it's too old to be opened on this version of macOS, or that your Mac doesn't have enough free storage space for the installation.
To confirm compatibility before downloading, check the minimum requirements for macOS Catalina, Mojave, High Sierra, Sierra, El Capitan, or Yosemite. You can also find compatibility information on the product-ID page for MacBook Pro, MacBook Air, MacBook, iMac, Mac mini, or Mac Pro.
Make a backup
Before installing, it’s a good idea to back up your Mac. Time Machine makes it simple, and other backup methods are also available. Learn how to back up your Mac.
Download macOS
It takes time to download and install macOS, so make sure that you're plugged into AC power and have a reliable internet connection.
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.
- 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
Install macOS
Follow the onscreen instructions in the installer. It might be easiest to begin installation in the evening so that it can complete overnight, if needed.
Can I Delete Install Macos High Sierra App
If the installer asks for permission to install a helper tool, enter the administrator name and password that you use to log in to your Mac, then click Add Helper.
Can I Delete Install Mac Os Sierra App Download
Please allow installation to complete without putting your Mac to sleep or closing its lid. Your Mac might restart, show a progress bar, or show a blank screen several times as it installs macOS and related firmware updates.
Learn more
Can I Delete Install Mac Os Sierra Application Is Damaged
You might also be able to use macOS Recovery to reinstall the macOS you're using now, upgrade to the latest compatible macOS, or install the macOS that came with your Mac.