Thanks a lot for advices and your help, i'll test it and i'll post the result, positive i hope..

in my experience problems like this with drives like these are caused by firmware damage or head(s) failing. in the latter case you will not be able to clone it yourself.

also if I were you I would not remove power from the drive again as it can easily go right back to not being detected

_________________
You don't have to backup all of your files, just the ones you want to keep.

I just started with Media Tools Pro and cycle-clone the 250Gb drive(with problem) to 500Gb new drive.
I dont select reverse-clone as a "last chance"..
So far:

Source: Ide 001
cylinders: 484521
heads: 16
sectors: 63
total: 488397168

destination: ebios hdd 82h
cylinders: 60801
heads: 255
sectors: 63
total: 976773168

CURRENT POSITION:
cylinders: 2
heads: 93
sectors: 17
lba : 38005

time remaining: 8299 hours (LOL)
errors so far: 19
progress indicator: 0%

I dont now if these are good or bad, what do you think?

@drc
You mean firmware in service area, am i right?
Both of cases i dont be able to clone it by myself i think, because i cant access it without pc3000 and try to fix firmware..

One or more heads on that drive is dead.

_________________
www.datarecoveryne.com

After 5+ hours Media Tools Pro became extremely slow when retries to read an error so i stopped it at:

Final POSITION:
cylinders: 37
heads: 227
sectors: 19
lba : 608724

time remaining: 3689 hours
errors so far: 135
progress indicator: 0%

Drive become inaccessible again in both computers, so i give up again..untill my nervous system calm down at least..
Thanks a lot again everyone for your support, wish you happy and successful recoveries!!

Hello to you all.
It happens that I have a very similar problem with a WD HDD of a friend.
For me it happende like that: The HDD was attaced to an external USB enclosure and work fine.
When I wanted to attach this HDD direct inside the very same computer, I had the same problem. The HDD was not seen by BIOS or Windows Disk Manager.
However if I attach the drive to the external USB enclosure, it works fine.
Searching for a solution I come across this forum.
This is a very strange behavior. It might be that the external controller use another means of comunication with the drive.
Enyway I thought it might be hepfull to giannis267 in order to recover the info from that HDD.
It would be excellent if some specialist could explain that behavior so we can mind it in the future.

Here is the techical details of the above:

WDC WD2500AAJS
Western Digital 250GB SATA II [WD2500AAJS]
WD CAVIAR - Blue
S/N : WCAV2H040857
MODEL NUMBER: WD2500AAJS
FIRMWARE: 00L7A0
DATE: 25 IAN 2010
DCM: DHNNHT2AEN
COUNTRY: THAILAND

ENCLOSURE SPIRE SP176ISUO-BK-EU (ide+sata)
http://www.spire-corp.com/main/product_ ... ProdID=838
WITH CONTROLLER JMICRON jm20337
http://www.jmicron.com/JM20337.html