Our schools network is going crazy, first i thought it was a problem with the switch(24 Port DLink) but we changed the switch and only plugged in the cable that goes to the server and a computer but it doesn’t seem to locate any computers on the network, but sometimes it works fine without giving any trouble. we have 5 Switches which connects each other and all the computers in the network and all are handled by a server, the funny thing is all the PC’s upstairs(which uses another switch) are working fine most of the time but the PC’s in the ground floor doesn’t seem to have any connectivity most of the time, last night it worked and today morning it didn’t and again now its working but it doesn’t allow any access to any folders on the server. so i’m really clueless of what is happening right now. so please advice on what i can do, it is definitely not a virus on the server as i have scanned it with Kespersky.