Lets face it, the only reason you'll buy this is because you're being bent over the barrel by your college's math department. The publisher of this product knows this full well and their tech support department takes it into account when dealing with you.
When my copy of this product arrived I tried to use the code to register in my course, but MyMathLab said the code was "not found." I double checked everything and finally called tech support, who made up about 6 different excuses to simply get me off the line. Next, they said to contact Amazon because the kit was from a third party and that instead I should purchase a key from them - for $77. I refused and told them this product was clearly from their company and should give me access to MyMathLab as it was advertised, but failing that they should tell me exactly what the key was for.
The customer service agent finally said they would send the key to "tier two support" who would help me "soon." Two days later they hadn't contacted me through email, as was promised, so I called the customer support line again. The representative only said that tier two would be in contact with me "soon" and that they had no specific time, but again offered to sell me a key over the phone.
It has now been two weeks without hearing from "tier two support" and I had to buy an access code directly from the publisher, which is exactly what the company wanted. Thankfully Amazon was great about accepting the return.
This issue reflects very poorly on Addison-Wesley and Pearson Education, but frankly, they have no reason to be helpful. If you've purchased this product it's because you're forced to and if the code doesn't work, your only other courses of action involve either dropping or failing the course. Good luck with that.