How to recover old *.pst file

Hi,
i am Santosh,i just remove and reinstall office 2007. But after install office im not getting the .pst file which was priveously in my PC.
Please help me how to recover the old .pst file

Im using Wndows XP and the mailing system is Exchange but in OWA. Actually the thing is that with out taking a backup i just removed the office 2007. and installed it again.Now when im going to configure outlook im not getting the PST file which resides in the difult location. How can i get the old pst file