You may experience intermittent communication failure between computers that are running Windows XP, or Windows Server 2003, if the network adapter is configured to use checksum offloading and the Windows Firewall is turned on.
To workaround this behavior, turn off checksum offloading on the network adapter:
1. Open a CMD.EXE window.
2. Type the following command and press Enter:
REG ADD HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters /V DisableTaskOffload /T REG_DWORD /F /D 1