Forgot admin password for used Mac

BrandyKay559 wrote:

Forgot Admin password to used MAC all in one just got. And no internet setup yet without it

It sounds like the previous owner did not properly prepare the Mac for sale by using the instructions in the following Apple article:

What to do before you sell, give away, trade in, or recycle your Mac

You should return it for a refund, or have them perform all the steps in the article I linked so that they are no longer capable of managing this Mac and it has a clean version of macOS on it. Even if they do this for you, I would still do the "erase" section of the article just to be safe.

According to the Apple article I linked, if you can perform the "Erase All Content & Settings" option, then you may be able to reset the Mac to factory defaults, but it is only an option for the 2018+ T2 or M-series Macs.

See: If you forgot your Mac login password - Apple Support

For best support, please specify the exact Mac model (and year of introduction).

• Identify your MacBook Pro
• Identify your MacBook Air
• Identify your MacBook
• Identify your iMac (← probably this one, for “All-in-one”)
• Identify your Mac mini
• Identify your Mac Studio
• Identify your Mac Pro

Else this site can return the common name from the serial number: Check coverage - Apple

An Axxxx number (where xxxx is four digits) would also be etched or printed on the case somewhere.

If you remember, can you specify the version system software (“macOS”)? Possibly this is shown at startup before the login request.

Hi,

If you don't mine the data on internal drive, start up from Recovery Mode, then reformat and reinstall macOS.

https://support.apple.com/en-au/102518

If your Mac is tied with previous owner Apple ID, you'd better return and refund it.