I can’t install OS again I’m on a second hand 2007 Mac that runs el capitain I cleared the drive and I want to install again for a complete fresh Mac but it won’t let me now I can’t use my Mac at al!
iMac, OS X 10.11
See if you can boot into Recovery Mode using Command + R or Command + Option + R.
https://support.apple.com/kb/HT204904
Or if you have access to another Mac you can download and create a bootable macOS 10.11 USB installer.
https://support.apple.com/en-us/HT201372
Otherwise if your computer can run macOS 10.6.x Snow Leopard, then you would need to boot from a retail copy macOS 10.6.x Snow Leopard DVD (or your original macOS DVD if it contains Snow Leopard). Once Snow Leopard is installed you can download and install macOS El Capitan.
This all assumes your computer can actually run macOS 10.11 El Capitan.
See if you can boot into Recovery Mode using Command + R or Command + Option + R.
https://support.apple.com/kb/HT204904
Or if you have access to another Mac you can download and create a bootable macOS 10.11 USB installer.
https://support.apple.com/en-us/HT201372
Otherwise if your computer can run macOS 10.6.x Snow Leopard, then you would need to boot from a retail copy macOS 10.6.x Snow Leopard DVD (or your original macOS DVD if it contains Snow Leopard). Once Snow Leopard is installed you can download and install macOS El Capitan.
This all assumes your computer can actually run macOS 10.11 El Capitan.
Temporarily unavailable when on disk utilities
