I would start by uninstalling that xfast lan. It's not a driver, it's a program that acts as a network flow control, giving priority to programs that you select etc. These can really gum up the works when they don't work correctly.
Once the network adapter is working again, you can reinstall this program if you'd like to, but it's best to make everything as simple as possible to diagnose the problem.
Next, you can check if the network adapter is turned off in the bios by checking in the device manager within Windows. If the network adapter shows up as a 'generic/unknown network device/adapter' or some descriptor like that or if there is one labeled with the intel lan/device part number, then the adapter is turned on in the bios.
If no named or unnamed network adapter is showing in the device manager, then you'll need to enter the bios and find the 'Chipset Configuration' under the 'advanced' tab.
You'll want to check the 'onboard lan' tab about half way down the page here. It should be enabled.