I must be hard on laptops. ASUS laptop #1, 3 years, died twice during that time, third out of warranty (cause of death: GPU failure in all cases - bad set of nVidia cards). HP laptop, 2 years, died out of 1 year warranty (display and hard drive failure). Dell laptop, 2 years, died just out of warranty (power supply spiked, most internal hardware dead, caught fire). ASUS laptop #2, died 6 months in, fixed under warranty, died again 3 years in (GPU kept separating from its slot in the motherboard, eventually failed). ACER laptop, died in 2 years, just out of warranty (Hard disk, couldn't get Windows back on it without paying ACER to do it, not worth it because it was a cheap travel laptop).
Linux/XP desktop, formerly Windows 98, 16 years and counting. Still runs my backup server.
Wife's desktop - ~8 years old currently Windows 7 (originally XP with free upgrade to Vista, if I recall correctly), has had motherboard/CPU/memory replaced 4 years ago and added drives. Had a recent power supply failure that fried the Windows drive, so reinstalling Windows on a new drive then I'll see what I can save.
My current Desktop 3.5 years old, only GPU replaced, mainly to run modern games. CPU was fairly high end at the time and still valid for most.