This might be well-known, in which case sorry for wasting your time. It can be inconvenient to have one or several copies of XWin remaining after exiting Cygwin. You can do "kill PID" but for this you need to know what the PID is and then type the command explicitly. A command (or script) which will kill them all stone dead without previous reference to ps is
kill `ps | grep XWin | awk '{print $1}'`
Put it in .bash_logout? Or wherever suits.
Fergus
