Slow Server Response and Hangups

We have a small network (part of a much larger domain) of about 120 users. For about four weeks now we have been experiencing hangups from the shared common drive off the server. When people would try to navigate into a folder, it would hang, whenthey tried to open an Office (97) document, it would hang and never finish opening or saving. First, we pulled Norton CE off the server, that didn’t fix it. Then we reinstalled NT over itself. That didn’t fix it. It would work fine until about 11:00 in the day then it would start acting sluggish and begin locking up. There is absolutely no trace of Norton CE anywhere (serverrs/clients) and we are running Win 95 on all the clients, SP6a on the server. Any ideas?