Relative: That's one of my biggest annoyances...no one wants to take responsibility! I had a dud modem in my computer (purchased in '96 and since donated for some sort of gruesome computer cadaver experiment) and no one wanted to accept responsibility. At the time I found the identical model of computer at another 'puter store for $200 cheaper, but it was "refurbished"...when I asked the sales guy (first day on the job that very day...oy!) what was refurbished, he said "I think it's the modem". And I think the company knew about it and wasn't fessin' up to those models that were already sold.
Well, the software and software repair industries usually operate with a policy of no warranties whatsoever (read your Windows license agreement & you'll see what I'm talking about) unless you have some sort of maintenance contract with them. Course, this helps the hardware makers too coz in some cases they can shift the onus to the software makers.
If I fix a machine I'll have the person sign a statement saying their computer was working at the time they paid...with no guarantees past that point.