I've had four computers, all of which lasted about four years, and only one died on its own, although "useful" life is easy to appreciate.
My first ever computer came in 1993 - a 486, that needed a boot-disc-floppy to play Rebel Assault, but did just fine with SimCity 2000 and X-Wing. That more powerful computing even existed never occurred to me, since I only knew one other person with a computer, and all he had was Space Quest 2 and the original Warcraft. I don't know exactly what happened to that box, but I remember one day in 1996 it just wouldn't display anything.
It went to the Great Hardware Store in the Sky in time for Christmas, and the best workhorse I ever had replaced it - an NEC of some description, with 133mhz processor and 16mb RAM. I had to upgrade to 32mb to play Age of Empires 2... Ah, what halcyon days were those. I loved that computer, and it tried its damnedest to do anything I asked it. Never let me down, never gave me trouble. Then in 2000 my Dad tried to install a satellite Internet provider on it while I was out of the house, during a lightning storm. He never admitted to it, but there was a brand new desktop all set up in the kitchen when I came home.
Billed as "The world's best gaming machine" it was the eMachine Monster, complete with 700mhz AMD processor, the slot-shaped kind for those tiny motherboards they don't make anymore. We gave each other shit in equal measure from Day 1, when it threw a fit over installing Hexen and crashed when optimizing Morpheus. Installing Windows XP on the advice of my Taiwanese compadre only made it worse in ways I can't remember. By some miracle, I managed to install a new graphics card - as a huge fan of Daggerfall, I got Morrowind at launch, and the Monster nearly burst into flame rendering the prison ship. It just kept picking up problems: a virus caused the NT System process to crash-reboot Windows whenever the dailup login ran; I couldn't run programs without disabling a broken virus in the Taskmanager, which itself fought with the Taskmanager to make computing a daily wrestling match; the sound stopped working; and the harddrive occasionally made clicking noises but never gave up.
When I moved in with my mother in 2004, she bought me a Compaq Pressario, with 2.6ghz and 512mb RAM. When I recovered the Monster, it reactivated just long enough to transfer all my files over. I had dreams of wiping or replacing the drive and returning it to Windows 98 as an old-games machine, but it's lingered in the corner gathering dust for six years now. Meanwhile, where the NEC was faithful and the eMachine malicious, the Compaq was mildly retarded. Nothing but the harddrive actually remains from the original computer, and I have to reformat every year now. Although still perfectly functional, the Compaq accumulates quirks all the time, and I swear the performance is getting worse no matter how often I restore things. Now a 2.8 dualcore, with 3gb RAM and the best graphics card 2008 had to offer, it chugs on games from 2007 on anything but the minimum display settings. I imagine its nearly ready to retire, or at least truly replace the harddrive, but I'm just too reticent to do that. Building a new computer altogether would be nice, but I don't have a tech-guy handy anymore and I sure don't know how myself.