Monterey Update

One can start with and in this order;

1 - Shutdown computer by any means including Power Button.

2 - Disconnect any and all external drives.

3 - Connect to charger

4 - Restart and Immediately Hold the Shift key and keep holding until the Apple Logo is presented and then release

5 - If one is lucky - this Safe Mode Amy or may not allow the upgrade process to complete.

6 - If that does work - time to evaluate what Software, Personal Files needs to the removed. Goo computer practice it to Always keep at least 15 % the the Total Disk Capacity as Empty Space. ie: 128 GB CApacity Drive x 15% = 19 GB Empty Space at all times.

A - Should the above fail - options diminish.

B - To salvage Personal Data Transfer files between two Mac computers using target disk mode

OR

C- Use Disk Utility to erase an Intel-based Mac and understand Personal Data and Software will be lost and there is no recovery except if one has done A Time Machine Backup  is very useful and can be used to Revert to Previous Working macOS. 

D - Then How to reinstall macOS and this will require an Active and Functional Internal Connection. Connect via Ethernet Cable to Router for best results.

Worst case >> Visit a Genius at an Apple Store

aotclark wrote:

Hi all,

Macbook prompted me to do update and got 90% of way through then got 'error with update' message. Looking online this seems to be that there wasn't enough space and probably shouldn't have started update (or device shouldn't have allowed it).

I then got stuck in loop everytime turning macbook on, would start the countdown again, get to same point and then get same error. I can now no longer access my Macbook.

I bought an external hard drive after suggestion from other posts and did cmd R, formatted the external hard drive and tried again. This time it got stuck on 'less than a minute remaining' for about 2 hours.

The other issue here is my Macbook is slightly older and only has one USB C port, which I am using for the external hard drive and so cant charge simultaneously.

When I now boot it comes up with Apple logo, loads a standard bar for 30 seconds and then reboots the entire machine.

Any suggestions other than delete the entire disk/factory wipe?

Thank you

If I understand correctly - one is attempting to install Monterey directly to an external Drive ?

If above is correct - the destination of the installation of Monterey to an External Drive will not happen until the Internal Drive has been upGrading to Monterey First.

Please read below for explanation.

There are reports appearing on the ASC Forums regarding failed installation of Monterey on older Qualifying Apple Computers. In most cases this is related to having a NON Apple Original internal drive ?  

The EFI Boot ROM included in Monterey is verifying for Original Apple Drive and if not found , may Balk or fail to upgrade to Monterey. 

Reports indicate the EFI BOOT ROM is Required to Flash the Computer and is a  requirement for a Successful Monterey Installation.