If the keyboard of a computer you just bough don't work, you should immediately ask for a replacement.
Waiting a year to do anything is asking for trouble, and an expired waranty.
If your waranty is still valid, ask the store for a new keyboard, and to perform a general checkup of the computer just in case.
If you are past waranty, then you just need to buy a new keyboard and hope that the non working original keyboart and now dead replacement where not just symptome of some problem with your (USB) front and back ports.
Electro, July 2015