The problem is: With NT Server I'm not able to skip network card installation (how I could?), with NT Workstation I could. After installation, if I install network card, after rebooting System gives me an error, because it is not able to find the network (the system is not connected to a network). The only way that I found to not obtain an error every time I start NT is to remove each protocol (TCP/IP etc.) from network property. There's another way (more simple) to install a network card without errors?