Trying to change the ISO auto to manual?

I'm using nikon d80.im trying to work on manual mode. I can change the shutter speed and the aperture value but my ISO settings is still on auto.although i've changed the values in the menu, the view finder still says ISO auto. What do i do?

Auto ISO is still functional even in manual exposure mode.

The option to turn it off is in the Custom Settings Menu I think.

So what's wrong with looking in your user manual?

Look on page 43 of your user manual