Boot up problem?

Computer was turned off normally last night. This morning it can't start. I
set the first boot up as CD-Rom, second is floppy and the third is HD. No CD
in both DVD and CD-RW. So basically it will search CD-rom and then go to HD to
boot up. However, this morning the screen is stuck on the "Boot from CD-ROM".
It can't go to HD. In the selftest page, all four IDE devices are detected. I
have to change the first bootup device to HD. Then it can boot up again.
What's wrong with it? Thx

--文学城www.wenxuecity.com--