I've noticed that when programs add their directory to the PATH environmental variable, most append it to the end but a few add it at the beginning, before the windows directory. So it made me wonder, are there any noticeable performance implications to doing it one way or the other?
My gut instinct is that most PATH lookups are for system executables and if every PATH lookup checks each directory in order then there might be a small benefit to having the system directories up front, but I don't know if Microsoft is just smarter than that or if maybe it's just such a small difference that it's simply negligible.