Database data tranfer to another PC with same software

trying to help a friend to get the data base records he has on one computer to his other computer. He uses the same database software on both. One computer has winse and the other win XP. Wants to install win xp pro and I am afraid he will lose all his files, programs,etc as it will be a clean full version of xp pro. How can I transfer his data base records to his other computer into the database he has on it before I clean install xp pro?