Try the following.
If you have 10/100 net cards check the connection speeds if you have auto-detect match it to the speed of your network.

Change the network names to something simple make sure you haven't put any spaces in there.

If each laptop has the same configuration try updating the drivers.

If you are using a domain then make sure the client for microsoft networks is setup to log onto domain and make sure the workgroup name is the same. If all these fail try going into the properties of file and printer sharing and alter the setting for browse master and LM announce.

Thats my lot I can't think of anything else. Check different hardware, cables and NIC....

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And Control Enter STILL wont let me post a reply.