From THe Jargon File:
computer geek n.(Try this link to see the cross references --you might have to wait a bit for it to load).
1. One who eats (computer) bugs for a living. One who fulfills all the dreariest negative stereotypes about hackers: an asocial, malodorous, pasty-faced monomaniac with all the personality of a cheese grater. Cannot be used by outsiders without implied insult to all hackers; compare black-on-black usage of `nigger'. A computer geek may be either a fundamentally clueless individual or a proto-hacker in larval stage. Also called `turbo nerd', `turbo geek'. See also propeller head, clustergeeking, geek out, wannabee, terminal junkie, spod, weenie. 2. Some self-described computer geeks use this term in a positive sense and protest sense 1 (this seems to be a post-1990 development). For one such argument, chase this link.