[Delta Tango]

It seems that the author of the first article has some kind of grudge against Micro$oft, but the working conditions in some remote factory are not Microsoft's fault.
It's all supply and demand. A company requires a product to be made and factories offer their services. The one with the cheapest offer (or the one with the best balance of price and quality, depending on what kind of product the company wants its name on) gets the contract.
The company, which in this case happens to be Micro$oft, doesn't care what are the working conditions in that factory, not should it be held responsible for the treatment and pay the workers receive.
It is up to factories and the workers themselves to work out a solution that is acceptable for all and the legislation should be there to make sure it is "humane" or whatever you want to call it.

Look at it this way:
If you need to buy something you'll scout the market and probably find exactly the same product being priced differently in two stores. Of course you'll buy from the cheaper one.
Can you be blamed? Of course not. Why would you pay more if it's not necessary?
But by choosing the cheaper store, you encourage lower wages for the store workers.
The fact that this worker didn't produce that item, doesn't really matter, he or she produces a service which you buy, just like big corporations buy services of item production and, just like you, they search for cheapest source.

So, do you lose sleep over the fact that you try to save a buck or two every time you buy something?

Edit to add:
I'm not going to comment on child slavery other than to say that there are plenty of international organizations that are founded to combat it. The question isn't why child slavery happens, it's why is it tolerated by those noble organizations. (note sarcasm)