DVDrw booting problems

Hi,
I have seen a lot of things similar to this problem on here, but nothing that helps.
I have a sATA board with two sATA drives, also an IDE DVDrw and one IDE HDD.
The bios finds the first sATA and the IDE HDD, but not the other two. Windows sees them all and works fine, until now, when I really need to reload my instalation and can’t boot from CD.
The IDE HDD is master, DVDrw slave.
Have tried unplugging the HDD but still no luck.
Can’t work out why it would find one of each but not the others.
Any help is appreciated, thanks.