pri master drive - ATAPI incompatible

Hi im Sean from ireland,

I have 2 computers. 1. Compaq, 2. kit pc.

Both computers have good hardware and i decided to amalgamate the two.

The compaq is a stack and the kit pc is a tower.

I took the good hardware from the stack and fitted them into the tower.

Everything fitted and worked except for the ASUS cdrw/dvdrw drive.

When i turned on the computer an error message was displayed.
"Pri master drive - ATAPI incompatible, Press F1 to continue."

So I pressed F1 and "Boot Failure" was displayed.

It then asked for a floppy disc of which to boot.
As you can guess i dont have one.

So if anyone can help please comment.