How to Verify Ethernet Switch is working properly...?

I have running 60 PC's Network in my Lab and they're all connected via 3 Switches. In my openion the switches are working properly but I'm having some issue and the issue is " We have some examinar software installed in our every PC of our lab, when All users i.e around 32 PC's log in simoultaneously then they get error message of " Network Timeout" but if I log them 1 by 1 then they log in perfectly". Could you tell me where is the problem lies...? Is there problem with my Ethernet Cables or Switches...? Please Guide me.... Thanks

forget about your exam software, can your system ping each other and the server. from that you can rule out the switch problem.

I am suspecting you dont have a switch problem. The exam server software that allows clients log in might be the problem.
And if it is communicating with some online webserver, then the exam site might be poorly built.

yeah Sose you might be right it might be the software issue, because when the exam starts then there won't be any network issue even though the exam continuously communicating with the file server and in between exam no problem occurs. It just logging problem I'm having. The examiner software built by ACCA UK for taking Online CBE examination.

then try contacting ACCA for support via mail or yahoo messenger if you want it real time

Have you got any AV software ? I have seen similar issues with Sophos depending on the software. We used a Schools Information System that used to check the version of every file (hundreds of megs) on the network server during start up. Because Sophos was checking each file it would slow down the logon process.

Cheers

Wayne