Is the Vista system new or an upgrade? How much RAM does it have? How much free disk space?

>I got a vfp application (place in the server ) the system will share one folder (which place the database)
>all the PC will map that network drive and run the application .
>
>in XP , ME , the application very smooth and fast.
>However, when the PC is Vista OS ( 1st month run very smooth and then later the system seems hang and unresponsed)
>
>Please help , anyone know how to solve this ??