Thanks for the input. Sorry for not being specific enough. My problem concerns an additional drive.
SATA is enabled in BIOS. I have connected a SATA cable and a power cable, I guess that would be a 40-pin IDE cable, as shown is this guide:
SAMSUNG Hard Disk Drive - support - user guide
I have tried to swap sata cables between the two drives. The cables are both ok. I have tried to unconnect my old drive to see if my new drive would be detected then, But no. However, when I try the auto detection, it seems as BIOS is detcting something, because the auto detection window that pops up is up for ca 15 sec. But the drive is eventually not found.
Just to make sure, what is the old/new style power connectors like?