In IT jargon we sometime use [lamer][1].

> A lamer is widely understood to be the antithesis of a hacker. While a
> hacker strives to understand the mechanisms behind what he or she
> uses, even when such extended knowledge would have no practical value,
> a lamer only cares to learn the bare minimum necessary to operate the
> device in the way originally intended.

ADDED after the OP had added a limiting condition:

> I'm not looking for insulting or pejorative terms.

I guess you will hardly find any **single-word** term (in general, not only in connection with the computer literacy)  with a meaning "lack of something", especially "lack of knowledge", with *non-negative* connotation.

For the IT craft, any word meaning "computer illiterate" would be pejorative :) I cannot see any difference in connotation between *lamer* and *technophobe* or *digital illiterate* or *luddite* or *cyberphobic*. 

  [1]: http://en.wikipedia.org/wiki/Lamer