High Sierra Installation stopped on PRO

My Macbook PRO stopped under installation of High Sierra, saying cannot install on this computer. Now showing a blinking folder with a question mark. Cannot start anymore. How do I repair?


howapple - hello


The way MacOS Install generally proceeds is this:


a chunk of new software (actually a minimal system of the Incoming software) is ADDED to your boot drive. This does not replace you current system.

The start Disk is set to the newly copied minimal system

A restart occurs, booting to the new System.

If the Install gets in trouble at this point, your old system is still intact, it just needs to be re-specifed.


All you need to do is get the startup disk set back to the old system.


You can boot to recovery (Command-R), then quit recovery, and Startup Disk will be activated as you quit, and you can re-specify your Startup Disk.


You can Alt/Option Boot and select your regular Startup disk and tell it to proceed, Once Mac OS is active, be sure to use:

System preferences > Startup Disk ...


... to set the startup disk normally again.



if you would like help on making the Install work, please post the exact model MacBook Pro, including year and screen size, or the MacBook Pro 17,2 designation.