urgent help required

Hi team,

i am nagaraj, i am newbi in this database world. i required your help.

2 dyas back i formatted one of my client system. which is having postgresql 8.2 database & that was having data. but i am not taken backup of the data. 

1) how to take the data from the formatted harddisk. ?

2) how many folders or files will be their at base folder. When we install postgresql 8.2?

3) how to identify which folder contain which file. ?

Please help it is very urgent.

thanks and regards