It's priced right, it's ATX, and it's SLI certified, but I mainly want it because of the Lifetime warranty, but how do I know if the motherboard is responsible for something wrong to the system, either physical to the hardware and with the drivers or software if any?
It's a good MB. Personally I wouldn't buy it because it only has 4 SATA ports and I'm already using 7 in my PC, but if you can live with a DVD burner and 3 hard disks it's fine.
If the motherboard is defect you will see all sorts of things, from computer not starting to random reboots to data corruption. Sometimes these things can be fixed by BIOS updates, but not always. There's really no simple rule to tell if a certain problem is caused by the motherboard or by drivers or by some software. For example when I was getting crashes in Hellgate it turned out both Hellgate itself and nVidia's drivers were responsible.