How do you tell a customer that you can't fix his PC he has to buy a new one?

I appreciate your understanding, but unfortunately, after diagnosing your PC, I've determined that the repairs needed would exceed the cost-effectiveness of purchasing a new unit. The current hardware is outdated and may not support future software updates. I recommend considering a new computer to ensure optimal performance and longevity. If you'd like, I can help you find a suitable replacement.