Seagate Harddisk, 160 GB, recognized by BIOS but data lost?

[Armu]

I was reinstalling windows XP and had removed my slave Seagate 160 GB hard disk which had my data. After the format and reinstall when I reconnected my seagate disk the BIOS recognizes the disk but XP doesn't complete loading. The Windows XP loading screen with the blue moving bar keeps going on and on.I tried to connect the disk to my laptop using a external harddisk case with a USB connector but that does'nt work too.Any help would be appreciated. Thanks