Earlier quoted context omitted.
>> branded computers are more reliable than beige boxes. This is meaningless. The real question is how those compare to beige box that uses a decent parts. But Microsoft definitely has interest in helping manufacturers of brand computers because piracy is more prevalent in beige boxes.
Perhaps the difference is in testing. A large mfg, I would imagine, would test a configuration repeatedly before making it available, and then, once approved, the individual systems would go through burn-in, probably with more rigor than beige boxes. So even beige boxes with pricier (but unproven configurations) might suffer from grater failure rates. In addition, large mfgs might be able to demand better "lots" from…
Essentially you the consumer are doing the burn-in. Its cheaper for Dell to replace failed machines. The cost to burn-in (and the time!) is large.