I have a number of Netgear Ethernet cards and a nice fast switch from them. Alas one of the PCI Ethernet cards I have didn't work when I installed it in a machine, nor did it work in a different machine, and with either Windows or Linux. The box has "Lifetime Warranty" in big letters on it, so when I tried to get them to swap it for a good card, they said the warranty was good for three years only!
I'm going to write to them at my local (UK) office and complain, it's not as if replacing a £10 card is going to drive them into bankruptcy. If they don't honour the warranty, I'll write to trading standards to complain that it's a misleading claim.
If the warranty had only been for 2 years, I've had the card longer than that, I can understand, but if it says lifetime, then I expect it to be for the life.