Where is the Contacts stored in Windows 7 on Outlook 1010?

I have an issue. I have a user that I added their .pst file from their XP machine(C:\Documents and Settings\{user}\Local Settings\Application Data\Microsoft\Outlook) to their C:\Users\{User Name}\Documents\Outlook Files inside their clean installation of Windows 7 Pro x64 . Opened up Outlook 2010 and their contacts were empty. I would like to know where their contacts are stored .

Note: The XP machine had Office 2010 installed.

Yes they were . Before they got their new Windows 7 PC they were using a PC running XP PRO with Outlook 2010 ( Part of Office Home and Business 2010 ) .

Yes . I copied the .PST file from that location and pasted it to C:\Users\{User Name}\Documents\Outlook Files inside Windows 7 . Opened up Outlook and clicked on Contacts and it was empty.