Hi,
Check the event logs on the server and the suspect work stations, if anything is happening it should be recorded there.
A badly written app will slow a network but not crash the server.
If the server is abending it is more likely bad memory in one of the devices i.e. works ok until your app increases the load and the increase in memory usage cause allocation to where the bad chip is. Maybe the NIC ?
Any way the event logs should tell all.

>Hi
>
>I got complaint that my exe (vfp) crash the network.
>I look for help where do I have to start from? what is the common things that can cause it?