If i apt-get install ksh does it replace the default shell or only install it as an interpreter?

I'm getting the error: bash: ./fw_utils: /bin/ksh: bad interpreter: No such file or directory

If i apt-get install ksh does it replace the default show or only install it as an interpreter?

If it does install it as the default how do I switch the default back to bash?

From serverfault Gray Race

• I just checked it on my Debian box and it does not change the default shell for existing or newly added users. Existing user's shells are stored in /etc/passwd and can be changed with the chsh command. The default shell for new users is stored (in Debian) in in /etc/adduser.conf. Apt getting ksh did not alter either of these.

  Insyte : It does, however, add it to `/etc/shells` so it is ready to be used as a shell.
  From bk