>Addendum:
>
>If there is an option of not shutting down the application to fix indexes the better, but the best is prevention... because the application is being used heavily and as much as possible, no interruption at work...

If you can't fix existing hardware, probably the best bet is to run your app on a Terminal Server, and also have the data tables hosted on that same server computer. That way, everything is within one box and networking is not an issue. Stress on a LAN or WAN is much less than with native VFP data access, and if clients get temporarily disconnected for any reason, they can simply reconnect later with no damage to their session.

Of course, any computer acting as a Terminal Server or VFP data table file server should have a UPS and be backed up regularly.