Hi everyone .
Thanks to your help I understood the problem and now I have correctly configured
all the PCs that use the data on the NAS, where the NETDIR directory also
resides. Everything works correctly, but I'm a little disappointed by the
performance which I find below expectations.
I would like to ask your opinion regarding this configuration.
Do you think it is better an faster  to use a PC as a data server? Which
is the best configuration in your opinion hardware-software-bde-setting to
get the best performance? Thanks again for the help you want to give me.

Sorry for my bad English  ,Fabio