|The two most likely suspects are:|
1) hardware issue
2) driver issue
To start with, I'd look for newer drivers in both cases and I'd install them if you find them.
Also, I would reset the TCP/IP stack on both computers. To reset your TCP/IP stack first o pen a command prompt window (ie: Start >> Run >> type cmd and hit Enter) and perform the following command:
netsh int ip reset c:\resetlog.txt
Note If you do not want to specify a directory path for the log file, use the following command:
netsh int ip reset resetlog.txt
Then reboot the computer.
If none of the above works, you may have bad NIC'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.