Atheros L2 Fast Ethernet 10/100Base-T Controller Loses Default Gateway
Experiencing loss of default gateway after a restart. After restart, ipconfig shows 2 lines in default gateway. First line is 0.0.0.0, second is 192.168.1.1 (which is the correct value). However there is no connectivity. System details as follows: MB is ASUS P5GC-MX/1333, Core 2 Duo E7200 processor, Atheros L2 Fast Ethernet 10/100Base-T Controller (onboard). OS is Windows 7 Home Premium 64Bit. Uninstalling the driver for the NIC and then scanning for hardware changes and allowing system to automatically reload drivers fixes the problem until the next reboot.
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Did you try using a static IP address or setting the LAN speed to 100 Mbps Half-Duplex or 100 Mbps Full-Duplex instead of Auto? If that doesn't work, you could install a PCI NIC that has official Windows 7 support.