>Hi,
>
>We have an old Windows 2.6 multiuser application. If the program have been idle for around 30 minutes, it looses its connection to the network drives.
>
>The network is a Ethernet 100 Mbit on a NT server.
>The workstations are running Windows 98.
>
>Hope you can help................

In all probability the server is set to time out idle connections after a specified period of time; the value can be adjusted using the NET CONFIG SERVER command line utility on the NT Server. See www.ntfaq.com for details or read the documentation for NT Server that came with it.