We ran across an Old School QCPC (a custom built computer we built). It is about 16 years old and still running like a charm for our client!
Little slow due to the age of course. Our client is still happy with it and is really squeezing the miles out of it.

Just goes to show when you have a well-made computer that was built to last, easy to maintain and repair, you can get a lot more life out of it.
QCPCs are sturdy, robust computers a grade above many available at box stores.
So when is it time to get a new Computer? An easy answer would be – when it is no longer cost-effective to repair it or when it becomes slow enough that a new computer will make you more effective when you need to be productive.