Installed HDD but can't 'see' it

Hi. I've just thrown away my old PVR but kept the HDD as there are some telly programmes on it I want to keep. It's a Hitachi ATA/IDE 3.5" drive which uses a 'flat' cable. The only flat cable in my PC belongs to the DVD RW so I simply took the cables off the DVD RW and connected them to the Hitachi. On bootup, I was pleased to glimpse a balloon saying something like 'Hitachi device...