Linux booting problem

Everytime I bootup to my Linux redhat 7.1 computer,it required me to insert my bootup disk and
the following message display in the screen
“Press (or wait 10 seconds) to boot your Redhat Linux system from/dev/hdb5.
You may overide the default linux kernel parameters by typing “Linux “,followed by
if you like”
Can you please tell me how to tackle this problem and to allowed my linux redhat boot up normally
without using my boot up disk.
Thank you.