TFY unwisely agree to Do Something about 70-year-old in-law's laptop, which is 9 years old and running Word 2008 atop a version of macOS unsupported since 2018 …

You have a spare M1 Probook to upgrade him to. What could possibly go wrong?

Well, he's forgotten his login password, never had an AppleID, and his old machine doesn't recognize APFS filesystems for that old-time floppy-style SSD shuffle.

And the cable to the only SSD they have is flaky.

(Now back home, screaming quietly in Mac.)

NOTE: situation is under control, file transfer is happening despite obsolescence (you can't even update his old machine to a new enough macOS to support Migration Assistant transfers to his new mac).
@cstross target disk mode.. if there is no filevault.