Hardisk not detected in bios and windows

^ I stopped reading after the 4th "say"

@op, I would suggest updating your bios if available, next try some different cables if you have them. If you can do a deep format with the hdds tools I would try that aswell. Couldn't hurt.

Have a try on this: http://freeware-recovery.blogspot. [...] overy.html
Maybe it will help you. The operation is quite simple and you just do as it is said then you will get what you want. Hope it can help you.

Exactly how do utilities such as HD Sentinel or HDDScan detect your drive?

Is there any reason why you omitted to tell us what the "xxxx" in "WDC xxxx" is?

At the moment it looks to me as if the drive has an internal fault.

WD Caviar Green. the type is WD10EARS.
Just scan the HDD and detect incorrect size (2TB instead of 1TB).

is it possible we can detect HDD (under windows or DOS or linux), if the bios does not detect it??

You began by saying that your HDD is not detected in BIOS. Then you say that it is detected in a USB enclosure. Does BIOS see the drive's model number, or is the model number field blank, or does BIOS see nothing at all? Did the drive ever work, or is this a new installation? Have you tried limiting the SATA interface speed to 1.5Gbps via the OPT1 jumper?

Does the drive actually spin up, or is it jumpered (PM2) to Power Up in Standby (PUIS)?

If the drive spins up, but reports a capacity of 2TiB as opposed to 2TB (max LBA = 0xFFFFFFFF), then this points to an internal fault.

You could try reading the drive's firmware modules:
http://community.wdc.com/t5/Desktop-Portable-Drives/Nas...

One or more may be damaged.

nop

the bios did not detect the information HD.
Now, the HDD is back to normal again.. strange, I was trying to use Ubuntu. and woalah...the ubuntu detected the HDD.
after that. BIOS detects the HDD as well.

THanks for all responses!