I had to scrap an HP Laserjet 2100 yesterday
Nothing wrong with it, except it used a parallel port lead (permanently wired in) while the replacment Win7 PCs we're installing don't have parallel ports
At a rough guess I reckon its around 13 years old and still printing perfectly
The online user guide dates from 2000
It could still be used in a modern office as a network machine if attached to a jetdirect card, or other print server. Those old HP machines were quite simply indestructible