There is a third kind of computer illiteracy.
Selective Computer Illiteracy is the mystifying phenomenon whereby a user is stymied by a computer because they--regardless of their literacy level on other media such as dead trees--are completely incapable of reading any kind of simple instructions the computer clearly prints on their screens.
This kind of person will reflexively dismiss the dialog boxes that pop up to explain their problem, and invariably ask a helpless bystander questions starting with "How come I can't...?"
Because everyone knows that computers can't tell you what's wrong. That'd just be silly.