TRYING TO UPGRADE MY 2017 MACBOOK PRO 13 INCH FROM SIERRA TO BIG SUR OS 11. IT STARTS TO LOAD AND THEN FREEZES

Big Isaac wrote:

I held down the power button down till the MacBook Pro went blank screen. Waited a bit and pressed the button again. The startup bar appeared and quickly progressed. As soon as it ran to the end the screen seemed to come on momentarily and then went back to startup bar. But this time the bar only progressed a very small amount and stayed there.

If your Mac starts up to an Apple logo or progress bar

https://support.apple.com/en-us/HT207019

Big Isaac wrote:

how can I upgrade my MacBook Pro from Sierra to OS 11 Big Sur? Tried once, it started to load and froze.

If you are frozen you can force a shut down by holding the power button/touchID for ~6-10 sec.

Reboot as normal and see where this leaves you...

Log out, sleep, wake, restart, or shut down your Mac - Apple ...

You are woefully behind in the macOS, you may have to stair-step your way up,

before the more contemporary Big Sur, at least High Sierra first... and try again

The older macOS installer backups on this server:

https://support.apple.com/en-gb/HT211683

verify you are using the Safari browser to download/initiate the macOS links.

How to upgrade to macOS Big Sur w/tech specs

https://support.apple.com/en-ca/HT201475

Tech specs—Big Sur

• MacBook (2015 or later)

• MacBook Air (2013 or later)

• MacBook Pro (Late 2013 or later)

• Mac mini (2014 or later)

• iMac (2014 or later)

• iMac Pro (2017 or later)

• Mac Pro (2013 or later)