Network card is initialized at 100Mbps speed rather than 1Gbps speed.
From the Start Menu, open the "Device Manager" snap-in.
2. Locate and expand the "Network Adapters" item in the list.
3. Right-click on the network adapter you wish to modify, then click the "Properties" context menu item.
4. Un-check the "Allow the computer to turn off this device to save power" checkbox, then click the "OK" button.
5. Within the Windows Task Bar, locate the "Network & Internet Settings" icon.
6. Right-click the "Network & Internet Settings" icon, then select the "Troubleshoot problems" context menu item.
7. Within the "Windows Network Diagnostics" wizard, click the "I'm having a different problem" button.
8. Within the "Windows Network Diagnostics" wizard, click the "Use a specific network adapter (for example, Ethernet or wireless)" button.
9. Click the "Ethernet" radio button, then click "next".
10. Windows will diagnose and correct any issues with the network adapter, then display a summary of the process.
11. Observe that the network adapter has reset to 1Gbps speed.
At times, especially when running multiple disparate motherboards on the same system image, it can come to pass that the network card of one or more of the systems defaults to a slower speed (100Mbps, for example).