Give details as to how you performed the Realtek Ethernet driver installation.
What Realtek driver version are you currently running?
Post a screenshot of the "Driver File Details" dialog from the "Properties-Driver tab-Driver Details" of the Realtek PCIe GBE Family Controller in Device Manager.
Do you have Cable or DSL Internet?
Launch "Control Panel - Network and Internet - Network Connections". Does "Local Area Connection" display a red "X"? If so, right-click on it and choose "Diagnose" from the popup menu. What does it tell you?
G74SX-A1 - stock hardware - BIOS 202 - 2nd Monitor VISIO VF551XVT