The access to the Red Hat

I have eventually installed the Red Hat 9.0 (I changed IDE configuration from my bios-put compatible mode), but now when everything is finihed I can’t have an access to the Red HAt…I have two systems installed in my computer…One is Windows XP and the second is Red Hat 9.0…
Now when computer starts its work, its starts with Win XP and no one prompt that there is also another system on it…
What can I do to make computer load Red Hat as well…
Thanks for the answer beforehand…