"Cancel" is the more meaningful word of the two. You've just told the user that something unexpected will happen if they proceed. "OK" can be construed to mean "OK, well then obviously don't do that!"
Eh, that's rubbish. I did IT support for almost a decade in two countries and not once did I hear anyone express confusion about that.
Eh, that's rubbish. I did IT support for almost a decade in two countries and not once did I hear anyone express confusion about that.