No hard Disk detected.

[#1]

When booting I get the message "No Hard Disk Detected" then everything boots up as normal and works OK.
Looking in the BIOS setup the CD/DVD Drive is detected first followed by the Hard Drive.
This message has always appeared since I got the computer nearly 3 years ago and as it does not cause any problems I Just ignore it but out of curiosity what setting in the BIOS (assuming it's that) is likely to be causing it ?

[#2]

It's possible that your system has two SATA controllers,  with one or both supporting RAID.  The message is appearing because a controller doesn't have a hard disk plugged in (because it's connected to the other one).
As you've noticed,  this won't cause any issues.
If you wanted to,  you should be able to determine which controller is being used,  and disable the other controller in the BIOS.

[#3]

Thanks for that.
I Guess I will leave well alone as it's causing no problems.