According to that, it changes based on the Windows version. Vista has the path in that answer, one comment confirms that the PowerShell path was added in Windows 7, and it's plausible that Windows 8 added something else.

But that's actually beside the point. That's the path that `%PATH%` defaults to, which isn't what we want here. My `/usr/bin:bin` suggestion was based on the PATH that `execvp()` uses if `$PATH` is unset. That's not actually the path that's used by default on a fresh system (that usually includes at least `/usr/local/bin`).