Can ping by IP but not by Hostname

Hi all,
I've searched Google and some threads on this site, but to no avail. I can't seem to figure out what's going on with my network.

I recently acquired 2 new laptops. I've formatted them and all computers on my network are running XP SP3. The problem is that I can ping certain machines by hostname and IP. However, the newer laptops I've put on my network can only be pinged by IP. Odd thing is that when I disable Windows Firewall, I am then able to ping by name again. Even a min or so after I enable the FW again, I can ping by name, but that will go away a min or so later. This can't be caused by any malware as they have fresh installs of XP with minimal apps installed as of yet.

Any thoughts?

 

That's strange... Typically you can't ping a Windows XP computer which has the Windows Firewall enabled because it drops the ICMP traffic. If you can ping a computer by IP address but not by name, that sounds more like a DNS issue. Is your router also acting as your DNS server on all of your workstations?

 

All workstations and Laptops are DHCP. Nothing is configured statically on my network. What's funny is that this is how I've setup all my home networks and have never had a problem.