Forums PostgreSQL.fr

Dear all,

I am pretty new with postgresql and pgAdmin and I made a beginner error.
I changed the hard drive of my computer and unfortunately (and stupidly I really admit) I have not make a backup of my database in pgAdmin3 before. Is there anyway I can manage to transfer it back from my old hard drive to the new one?
I look that up on different forums. I tried to copy the file "Data" of pgAdmin from the old hard drive to the new one but it did not succeed. Is there any hidden file that would retain information of my database still on the old hard drive?
If I re-install the old hard drive, would I be able to access the database back?

if anyone have any idea I would be really glad,
thanks