switch.exe was written by Mark Bradshaw and is part of the
Network Simplicity OpenSSH package.
cmd.exe normally or if it detects command line options
will switch to
/bin/sh. Grab a copy of the source from their
now unsupported package and
Place the resulting executable in
C:\Program Files\OpenSSH\bin and for those users applicable change
the password fields in
C:\Program Files\OpenSSH\etc\passwd to
Additional Cygwin Libraries
/bin/sh, which requires
some additional Cygwin libraries to run.