Warranty...i never registered it...take that how you want to!!!!!!
Once, i had an Asus motherboard and, when i bought a 56 external modem (yeah: that long ago ...), i found out it wasn't detected. After a while, i found out the problem: the COM 2 port was damaged which meant that i could either use the mouse or the modem, but not both.
I was lucky because i found this problem 1 week before the end of the warranty so i took it to the store i bought it from right away and it was fix @ no charge.
A few years back, i had a 9700 PowerColor video board and i had the distinct bad luck of it getting corrupt memory 1 month after the warranty was over ...
Back then, the warranty was of 1 year only.
Warranty has it's perks, i believe.