I have had a WD 160GB SATA hard drive in my PC but today morning it is not booting. I then connect it to the another computer which contains Seagate 360GB SATA hard drive. I connected all the power, SATA cables correctly and when I turn on comp, it shows on the bios that my WD 320GB is the 1st and Seagate 160GB is the 2nd HDD but it dosen't boot. However, when I disconnect 160 GB HDD it boots normally. The hard disk contains some important documents Pls suggest me to solve the problem or to recover all the data.
You may have a bad drive. I've seen hard-drives go bad (the board, not the platters), where they cause whatever system they are in not to boot.
The good news is that the data is almost certainly just fine. You can try to use that drive with an external USB enclosure it may work, although not likely. Or you can check ebay for an exact match to the logic board on the drive to replace.