I don't entirely understand this, but I suggest that someone who uses
Windows read it and DTRT.
This doesn't seem to be Windows-specific at all; he says that using the
system clipboard while running a (long/repeated) macro that uses Emacs'
kill ring loses because they're constantly being synchronized. That
should be true on any system with interprogram cut/paste.
He also attributes a perceived slowness on W32 to this synchronization,
but that seems unlikely (I'd think it more likely to be slower redisplay
or so on W32).
So, what he really wants is to not have the system clipboard consulted or
updated during the execution of a keyboard macro, when the kill-ring
should be "internal" data. If that sounds like a good idea, I can whip up
a patch.
Davis Herring