I have a hard disc ST9500325AS. The same is showing 8.4GB in BIOs. How can i recover the data

Seeing a drive size reported of 8.4GB is usually a BIOS limitation, and not a fault with the drive at all - you can search the web for more details. Google is your friend

Therefore you might get more help if you explain a full history to this situation (e.g. where was the drive used before?; are you are trying to recover data from it in a different system, and if so, then why?; are you sure that you didn't change the BIOS settings?; why do you think this is a problem with the drive? etc. etc.)

I would think that any BIOS that supports SATA would be recent enough not to have the 8GB limit of some older BIOSes.

Could it be that BIOS is calculating the capacity based on the reported CHS parameters rather than the LBAs, in which case the drive may actually be reporting 0 LBAs ???

The OP could verify this using a bootable CD version of SeaTools.

_________________
A backup a day keeps DR away.

I agree completely if this system has native SATA support (the OP hasn't said that it does) - and that's why I asked the supplementary questions There is no sign in the OP's post that this specific coincidence in reported capacity, and that old BIOS limitation, had been considered.

This coincidence might make sense to them now that I've raised it e.g, is the drive now being used in an old machine (with that 8.4GB BIOS limitation) via a SATA-to-PATA converter board...? Hence my supplementary questions


Depends what you mean by "reported" - if you mean reading CHS values from the MBR, then I've never seen a BIOS which reads that to report capacity (which, of course, doesn't prove that this isn't possible ). If you mean reported in the Identify Device response, then that would (as you say above) affect any larger drives, and hence doesn't make sense if the BIOS is supposed to support larger drives.

IMHO it all comes back to the OP needing to explain the history of this drive; where it got used before; what is different between that system and the one where it is used now etc. etc. Without that info, then how he/she got to this situation is all guesswork and hence a potential waste of time, if such guesses are wrong...

thank you for replyng.
i had put the hdd in a desktop and there is no restriction on bios as it detects other HDD of 500GB.
This particular HDD is showing 8.4GB in Bios

Test your drive using a bootable CD version of SeaTools.

_________________
A backup a day keeps DR away.

However since you aren't answering my earlier questions, I don't have enough information on your problem to make it worthwhile spending any more time on replies at the moment