but there are caveats.
If your attention was drawn to the fact that there were faults, or parts missing, or if the faults were such that it is reasonable to expect that you would have spotted them you do not have the right to expect replacement or repair within six months of purchase under the terms of the sale of goods and services to consumers regulations.
You do however, still have the protection of the Sale of goods act, which states that the machine must be fit for its purpose - that of being a computer.
The problem in these cases is often one of proof - what proof is there that the retailer didn't have a notice by the machine saying "there may be components missing or damaged from/in this computer, it is not sold as new, and you purchase it entirely at your own risk". The shop might say there was, you might say there wasn't, and neither of you can produce proof that you're right.
Are you absolutely sure that the onboard speakers and trackpoint haven't been disabled in the Windows device manager settings?