I used to be a Geek Squad Employee, and let me tell you 160 is nothing for installing a harddrive. Well I'm just kidding, it's a lot of money, but all the BS you have to put up with from clients, it's not worth it. Something you enjoy so much, working on computers, will become the worst job once you have a few bad customers. I don't know if people really don't know what the hell they are talking about, or just want to hassle you so they can try and get you to drop your price, but initially there are so many stupid customers. Second, like many have already said, once you are done with the job, expect a phone call back because they can't get stuff to work.
If you do decide to go through with all this, I wish you the best of luck. I tried starting my own business earlier this year, but realized after working at Best Buy it was going to be a bad idea. My suggestion, which someone already stated, would be to try and find a local PC shop to work in, and understand the type of work it really is before deciding to throw your number out onto bus stops....