disk error vs hardware error

disk error and hardware error both are nouns.

Word	Noun	Adjective	Verb	Adverb
disk error	Yes	No	No	No
hardware error	Yes	No	No	No

As nouns, hardware error is a hypernym of disk error; that is, hardware error is a word with a broader meaning than disk error:

disk error: error resulting from malfunction of a magnetic disk
hardware error: error resulting from a malfunction of some physical component of the computer

disk error (noun)	hardware error (noun)
error resulting from malfunction of a magnetic disk	error resulting from a malfunction of some physical component of the computer