"I am unable to complete the software update on my MacBook Pro: I cannot software update on my MacBook I do it wait to complete but it shows as if still needed an update"
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Successfully Updating a Mac:
What's the model of your Mac? What are you looking to update to? Apple has a tendency for providing updates for 7 years after the release of a device or operating system, and then stops providing them.
A. Back Up your Mac First:
Be certain you Create a Time Machine Backup of your Mac, so that way you can have something to restore your Mac from, should anything go wrong with the reconfiguration.
B. Create a New Administrator:
Try updating with a new administrator account. Once all is upgraded, trash this Administrator account you created to perform he update.
C. Connect Using Ethernet:
For a more reliable connection, connect your Mac using Ethernet. For a Mac without an Ethernet port, this is the adapter to use: The Belkin USB-C to Gigabit Ethernet Adapter - Apple