Lets say that you went down to the video store to get the latest movie on DVD, only to find that 5 other video stores opened next door to it. Now you have 5 video stores in a line and you aren’t a member at any of them, and they all have the DVD you want in stock. Which one are you going to choose to buy from? Since the DVD you want is identical at each store you would most likely go for the one with the best price.
But this doesn’t happen in the real world. You choose your video store over another one for a certain reason; there is something different about it. It may have the friendliest staff, the best movie range or simply the closest to you. Every time you go out to buy something you are making this choice. So, what makes your business different?
In the computer repair business there are many things you can do to make yourself different. Perhaps all new systems you sell are fully patched with an anti-virus and anti-adware application pre-installed. You may rule that if you don’t fix the computer there is no fee or offer a free PC report for every system brought into your shop.
It is a good idea to incorporate what makes you different in your businesses slogan like in the example of the “plays every time, or its free” video store. In fact, this seems to be the purpose of many businesses slogans.
Hungry Jacks (Australias Burger King) has the slogan “The Burgers are Better at Hungry Jacks” letting you know their burgers are better than their competitors (ie. McDonalds).
Coke used to use “It’s the Real Thing” implying that Pepsi isn’t the real thing?
For your own business you could say that you are longest established PC Store in your town, largest, the friendliest etc..
Anything to make your business different.

Articles
Blogs
Kits
Forums

I agree fully. We use this concept in our slogan “Doing I.T. Right”. We’re implying that WE do it right unlike the others. I get alot of business who have gone to competitors only to bring it to me later because we’re “Doing IT Right” and the competitor didn’t. Word gets around it’s not just a slogan, it’s our way of doing business.
There are tons of ways to differentiate your business from the others. Two of my all time favorites are charging a little more for our service than the competition (perception of value) and the lack of arrogant technicians. My biggest complaint with the pool of technicians we have to choose from to hire is that most of them are far to condescending in conversation. They may be good workers in a back room somewhere, but not in a high visibility, client facing role.