How would I talk about something that is either a laptop or a desktop, but not a smartphone or tablet? Is "computer" ok, even though technically speaking, smartphones and tablets are or contain computers?
For example, how would I say something like "If you're on a [computer], click on the arrow to see the relevant chat message"?
Best Answer
I would suggest computer (in agreement with Dan Bron's comment).
You're not trying to win a medal for ontology, you're trying to point people in the right direction. Laptops and Desktops are commonly called computers, those other devices are not.
This would be strengthened by adding a contrasting reference to something like mobile device, mobile, or phone nearby. (For example saying how such things are not available from mobile devices or are available elsewhere).
I think using these terminologies would minimise genuine confusion at the slight expense of annoying pedants who could think of counterexamples (You are actually assisting these people as well, in satisfying their need to find examples with which to demonstrate their linguistic superiority to others).