>Backend Database?
>What does that mean?
>Is that SQL Server?
>I've only put the DBF Files at the network drive.
>
>Thanks

Back-End Database refers to Client/Server database that is being in used. Anyway, its now clear to me that you are not using C/S technology.
Slowing down of application has may factors involved. It is a question of how you designed your system. Here are some IMHO tips:

1. Optimize your syntax and index using Rushmore Technology of VFP (reference : Using Visual Foxpro 5 pg871, pg173)
2. If you are using Windows NT as Network OS then double check the settings (do not activate Screen Saver not compatible to NT OS, etc).
3. Do not use SET FILTER Command in exchange for Relation object on Data Environment (especially Master/Detail modules).
4. We rarely use FOR clause on SCAN, COUNT, SUM, CALCULATE etc. We use WHILE clause coupled with SEEK syntax (seeking the first record before SCAN etc.).

Above are just partial things to consider in developing Enteprise applications.

Hope it helps.