Thunderbolt is seen as PCI-Express so it should not need drivers from the notebook, only device part, and there won't be a "Thunderbolt" listing in the device manager. At the very least it should show up in Windows as an unknown device.
1) Please check the specification on the box of your G46VW as Thunderbolt is optional. Retailers should list it accurately.
2) If your model definitely has Thunderbolt, what model external HDD are you using exactly?
