Before just touting stuff, at least provide your sources.
Windows is not compliant itself. It is the combination of the software used and OS.
Compliance is very expensive, and it is much more expensive on windows than linux.
Sorry, but quickly googling this time didnt cut >)
I think you've betrayed your skillset (again). Level 1 vendor compliance is expensive. It's not just expensive in CAPEX it's also expensive in OPEX. Many vending machines would only need level 4 compliance.