> ...PLCs still run XP, because they use some very specific piece of hardware whose vendor went out of business, so there are no device drivers for more recent versions of Windows.
There are alternatives to this problem but many companies don't have the budget, don't want to invest, or don't know that these drivers can be rewritten to new platforms with reverse engineering.
I don't know if you know much about the automation industry, but reverse engineering a driver so you can run it on a newer PC would be an unacceptable risk. Are you confident in your driver being able to safely control the industrial equipment? A coal train which costs $1000s of dollars a minute for any down time? Are you willing to take the blame or deal with the lawsuit if something goes wrong? The other side of the coin is that some companies do have the budget and can invest in newer technologies, but the cut over to new equipment is just down time they cannot afford - so be it if there's a risk of larger down time in the future.
Risk has a price. I am taking this kind of risk for several projects. I understand that the customer doesn't like to take the risk, even when they have the budget.
Even so, there are formal ways to show you are solving a problem with certain probability. These kind of projects require extensive testing.
There are alternatives to this problem but many companies don't have the budget, don't want to invest, or don't know that these drivers can be rewritten to new platforms with reverse engineering.