The Cygwin Linux emulation environment does not have an uninstall
utility.  It is possible to uninstall but it requires special steps.

The Xythos WebDAV server requires installation of PostGreSQL.  The
services required by the installation of Xythos WebDAV Server must be
stopped and uninstalled before Cygwin can be removed as shown in the
steps below:

   1.) Open a Cygwin window as the system administrator.  Issue the
       following commands, in order
          net stop postmaster
          net stop cygserver
          cygrunsrv --remove postmaster
          cygrunsrv --remove cygserver

   2.)  Close the Cygwin window with the EXIT command.

   3.)  Delete the entire Cygwin directory (for example, C:\Cygwin)
        and remove any icons that have been created.

Operating System and Release Information