Network Monitoring Options?
Nom du Keyboard asks: "We have a LAN network of 7 servers and about 400 PCs. Every so often I'll notice immense slowdowns, from minutes to occasional delays of a couple hours, while getting data from various servers, and it happens from more than just my PC. So far we haven't had any way of determining if a server has suddenly gotten tied up, or if there is some failure in the communications backbone. Without a lot of money to spend on this (I think it's more important than others right now), what cheap or free monitoring options are there available that can map and isolate problems in a network of this size?"
"Tied up"? "Failure in the communications backbone"?
My suggestion is to hire somebody who knows things about computers. Your language suggests you are a layperson. Not being a computer expert isn't bad, but not being a computer expert and trying to do the job of a computer expert is.