TL;DR: What does the refresh feature in Windows do?
I've seen it in Windows 7, Vista and XP but not in Linux (I dunno about a Mac). You have to right-click on the Desktop and hit E or click "Refresh" to use it.
Does it make your system faster or more responsive in any way? Refresh cache? Reload RAM?
I'm inclined to suspect that it's pointless and it's just there to avoid people releasing their anger in other ways, like the close button in lifts. Searching for "Windows refresh" just gave me a bucket load of posts about Windows 8's new Refresh feature. Refining that to "Windows 7 refresh" didn't help either.
Edit, for all you downvoters: yes, I realize the question may be dumb (<-- understatement); but you have got to realize that since childhood, this is what people around me assume and still think it does (I agree, they're not very technologically-competent people, but everyone from my family to my school's computer teacher and principal do this). And anyway, as a person whose only resources were limited to the people around me and Google (no one told to to RTFM then), I think I did a reasonably well job of researching and trying to find out the answer before posting the question here... <end of rant>