connected the HDD via an enclosure and USB to my other PC and eventually it say that there is an In/OUT error.
Does this mean that you are not able to get access to the HDD even using an external USB case?
It looks like the HDD is corrupt and in most cases the data could not be recovered on usual way.
Of course there are different Data recovery services but they charge between €500 and €1000 to attempt to salvage data from either logical or mechanical disasters.
There are also different tools which could be helpful like RecoverMyFiles from GetData, Ontrack EasyRecovery DataRecovery or Prosoft's Data Rescue II but you have to pay for all these professional applications…
Here is also a nice youtube video:
http://www.youtube.com/watch?v=vki3_zJZ8gY
Maybe it will work for you!