Apparently Microsoft claims that once a computer turns four years old, it'll cost companies $4,000 per computer they _don't_ upgrade, due to hardware failures and hardware related data breaches.
I find this _completely_ unbelievable. For one thing, several years ago I bought an entire stack of retired Core 2 Duo Dell Optiplex 960's from a college, where several have been put into near continuous use, and not one has suffered a single hardware failure since. And these are now 14 years old iirc.