My small home network is made from mac and Microsoft Windows NT Server 3.51. Recently, my weird problem starts: files disappear from mounted server volumes on Macs. It is not unusually for server to crash. I think that this is connected with mac and PC (I mean with theirs operating systems). Is there any solution for fixing this problem?
You are right when you say that this is connected with these two operating systems. To solve this problem, you should download Windows NT Service Pack 3 for Windows NT 4.0. It is Microsoft bug and you will remove it when you install this service pack. When you update your server, it would be good to try to find some updates for your mac, too.