In order to get two button mice or two button laptop touchpads to emulate 3 button mice for X windows change directories to /usr/X11R6/bin and then edit the startx script so that the line defaultserverargs= reads as follows: defaultserverargs="-emulate3buttons -multiwindow -clipboard" If you have downloaded the cygwin packages emacs or xemacs or both, you can use emacs in either form from the cygwin window to edit the file. If not you might try using Notepad to do the editing. Then after starting cygwin by clicking on the cygwin icon, simply type startx. If you have downloaded the X icon for starting emacs and Singular (a computer algebra math package) then you will need to go to the cygwin root directory c:/cygwin/lib/Singular/ and edit the file startxserver.bat and make the last line read: run XWin -emulate3buttons -multiwindow -clipboard -silent-dup-error You may also want to insert the -emulate3buttons options in the %RUN% Xwin line in the startxwin.bat file in directory /usr/X11R6/bin so that it reads: %RUN% XWin -emulate3buttons -multiwindow -clipboard -silent-dup-error