Dead Hard Drive,Need Critical Data

Hi ,
I have an all in one desktop, it was running windows xp sp2.

The other day we had a power cut and the computer went off.

Once power was back we tried to reboot,the computer is refusing to boot.

I believed that the hdd is dead, and so it is.

The drive is a Seagate 2.5 " Sata ,250 GB .ST925031 5AS
What I mean by dead here:

1. HDD spins and powers up.
2. It detects in BIOS.
3. I used an external adaptor of 2 types and connected it to another PC via USB, it shows in device manager under Disk drives.
4. It shows in windows disk management as Disk 1, unallocated 232 GB.
5. I tried to connect to a bootable Ubuntu pen drive, does not detect(the drive was connected via the same 2 usb interfaces)
5. Tried running a couple of Data Recovery and Partition Recovery softwares but in vain. need urgent assistance as the data on the drive is critical for us .