Praise the... !!! ... whoever merits a praise!
I was able to fix the drive, and retrieve most of the important data, even though some of it was inaccessible.
I don't have time now, but later I will explain in detail what were the symptoms, and what I did to solve the problem.

Seems to have no time

10, 9,8,7,6,5,4,3,2,1, 0 GO.................................................

Hi,
Please share or do not post

_________________
Regards
Amarbir S Dhillon , Chandigarh Data Recovery Labs [India]
Logical,Semi Physical And Physical Data Recovery
Website-> http://www.chandigarhdatarecovery.com

The HDD's parameters:

MDL: WD400BB-53CAA0
DATE: 13 NOV 2001
DCM: HSEHNQ2AH
S/N: WMA8H1230258
LBA 78165360
PCB: 2060-001092-006 REV A

The symptomps:

Drive is recognized in BIOS, but is unreadable under any environment (Windows, DOS with NTFS drivers, etc.)

MHDD reports the following after SCAN:

51 ERR INDX CORR DREQ DRSC WRFT DRDY BUSY AMNF T0NF ABRT IDNF UNCR BBK 10
[WDC WD400BB-53CAA0 ] [ 78,165,360] [ 4,045,065] [ EST: 19:16 ]
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS ACT [ 38131 kb/s]
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS ° <3ms :
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS ± <10ms :
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS ² <50ms :
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Û <150ms:
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Û <500ms:
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Û >500ms:
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS ? TIME :
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS x UNC :
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS ! ABRT :
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS S IDNF : 15863
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS A AMNF :
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS 0 T0NF :
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS * BBK :
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS [ 5.2% ] [ 5.2% ]
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Error: 4043535
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Error: 4043790
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Error: 4044045
Error: 4044300
Last scanned LBA: 4045319 Error: 4044555

Analysis:

MHDD's SCAN result implied that something is wrong with the drive's firmware modules.

Troubleshooting:

Based on rameez suggestion in another post I ran "HDD Repair 1.1" (which I no longer can find on this forum), went to WD, and chose "Translator Reload". After that I restarted the PC, and got back into Windows. Now the HDD was visible, and its root directory too! I was able to retrieve almost all of the data. I could not retrieve all of it, because the drive, apparently going bad, had a lot of bad blocks which later would appear as UNCs under MHDD.

I will try to fix the HDD, but it has already been released for trashing, so if I fail to save it, it would not be a problem at all.