You know your guy is one of them if:
You can't get ahold of him
He can always get you the same thing you just got online for 20% less
He has at least one other full time job
He just can't possibly explain what he's just done to get your computer working again; he's not even sure himself
It's always the fan
He's probably going to replace the fan
He says to you, "Where did you get THIS router?"
He tells you that AOL really will take over your computer and he's right. Skype, too. Norton, for sure. Get rid of all of it.
He always has an extra router/cable/modem/harddrive enclosure that you can borrow because he really doesn't need his.
Only HE knows the name of your computer
He's the only one who knows where your network key is saved
He's the only one who can restore anything if your computer has really crashed, including your network key.
He knows enough not to coach you through the motions over the phone.
Next to your significant other, your mom, your therapist, and your primary care physician, he's one of the most important people in your life.
He won't charge, but will accept money
He knows how much you need him but doesn't rub it in
He won't eat, but might take a cookie for the road
Both of you pray that one day he'll be able to send someone else out to fix your computer, but deep down you really enjoy your time together. So you dread that day.
He's always saying to someone on the phone, Soon. I'm almost done.
He'll be in your neighborhood next Thursday.