How do I reinstall macOS on an older MacBook Pro (2008–2010) without Apple Account sign-in?

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Level 1

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How do I reinstall macOS on an older MacBook Pro (2008–2010) without Apple Account sign-in?

Hello,

I have an older MacBook Pro (around 2008–2010 model). I completely reset/formatted it and I'm currently trying to reinstall macOS via Internet Recovery / OS X Utilities.

During the installation process, it asks me to sign in with my Apple ID to verify/download the OS. When I enter my Apple ID credentials, I repeatedly get one of these errors:

"An unknown error occurred"

An unexpected error occurred while signing in"

"plist parsing error"

Is this happening because Apple no longer supports old OS X authentication through the App Store, or is there a workaround to bypass the Apple ID sign-in? How can I cleanly reinstall macOS on this machine?

[Re-Titled by Moderator]

Original Title: Help me

Posted on Oct 16, 2026 1:12 PM

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Answer 1

Top-ranking reply

John Galt

Level 10

162,020 points

Oct 17, 2026 4:21 AM in response to bleron69

How can I cleanly reinstall macOS on this machine?

Boot from its original, grey, System Install DVD. Disc 1 of 2.

Those two discs must accompany the Mac's they shipped with from cradle to grave. Although Apple made Internet Recovery an option for certain Macs of that age, it had become an increasingly tedious and unreliable method due to the expiration of their security certificates, among other possible reasons.

Determining its exact model designation or exact model year as Grant Bennet-Alder asked will also help us determine your options.

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Answer 2

Oct 16, 2026 2:07 PM in response to bleron69

Exactly what model-year MacBook Pro and what screen size?

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