HELP! My hard disk isnt working :(

Hello this is my first post here i joined coz i am having really serious trouble with my hdd  

I have an Intel DH55PJ mobo, core i3 processor 540, 2gb ddr3 (all bought last week) and a wd 160gb (3+yrs old) and a seagate 250gb (1+yrs old).
The seagate has stopped working  

It happened yesterday when i formatted the wd. Windows xp was installed on the seagate.

Partitions setup like this
seagate-------- c:, d:, e:, f:....windows on e:

wd----- g:, h:, i:, j:

Till last week windows was installed on the wd.....but with the new equipment i thought i would install windows on the new-er hard disk.

There were errors on the wdc so i was moving around the data and formatting the partitions individually. So i formatted wdc's g: using partition magic to keep fat32 system on it and after that the seagate crashed.

When i connect the seagate BIOS doesnt work! PC hangs at the point where you are supposed to enter f10 to go to BIOS.
I let it stay there for about 10-15 minutes but it doesnt go beyond that screen.
This is an image of it>

Also this had happened a couple of times before.....but when i would restart it it would work again so i didnt think much of it.

Then i installed the windows on the wd to try and access the hdd from there.
PTDD partition table doctor did not detect the hdd, Seatools did not detect it...neither did partition magic or seagate file recovery for windows or spinrite6.0  

When i plug in the hard disk using a sata to usb connector windows does detect the hdd......to some extent
here's what i mean>>




The "disk drive" must be the seagate hdd.

Once it even detected the type of the hdd ie STxxxxxxx....but even then it didnt show up in My Computer.

I have checked all cables and ports so there's no problem there.
I reset bios by removing the button battery.
I changed jumper settings on the hard disk.
I was thinking about updating BIOS using intels integrator assistant but i didnt coz i read thats risky.....i am willing to try it though if it will help.

IS there anything else i should try or is the hdd lost? Please help me i have really important personal stuff on the HDD....its irreplacable   ANd i dont have a freaking back up FML