|the message said little or no connections|
I'm guessing you mean you received an error message stating the above? (For what it's worth, capitalization, proper punctuation, complete sentences and clarity all help us help you. In the future, try to use all the aforementioned when asking someone something).
If that's true then it sounds like a network connectivity issue. The first thing to check is the TCP/IP settings of the computers with the issues. Open a command prompt window (ie: Start >> Run >> type cmd and hit Enter) on both of the PC's with issues and on at least one that isn't having troubles. Run the following command:
Compare the output. The only setting that should be different is the actual IP address. The rest, subnet mask, DNS, default gateway, should all be identical. If they're not, that could be the issue. Simply post the output in a response here (of both PC's with issues, and one that doesn't) so we can have a look and compare.
If the TCP/IP settings check out ok, the next thing to do is make sure your network cables are good. If they are, then you can check to ensure you have the most recent drivers for the NIC's on those PC's. If you don't, download them and update the NIC's.
If neither of the above fix the issue, try plugging those two PC's into different ports on the switch.
If none of the above does the job, you could try uninstalling, then reinstalling the TCP/IP stack of the NIC's of the computers that are having issues.
If nothing works, then you may have to get new NIC's for those PC's.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.