Spawn New Cygwin Window from Within Cygwin

cygstart /bin/bash -li

Press 'Alt-F2' if you only want to open another terminal(mintty) in mintty, not from within a script. See 'man mintty' for other keyboard shortcut.

if you use the "default" cygwin console (aka cmd.exe) then:

cmd /c start /d "C:\cygwin\bin" SHELL.EXE PARAMS

and then replace SHELL.EXE and PARAMS by what you use:

• zsh: zsh.exe -l
• bash: bash.exe --login

i would advise you to use a better console like 'mintty' or 'rxvt', which you launch just by typing "mintty" (or pressing f2) or "rxvt".