On the G74SX, starting the laptop with the ROG key boots you into Express Gate, a BIOS extension that allows a quick boot with limited functionality to browse, manipulate photos, play music, and engage in social networking. Once in Express Gate, one of the optiions is to "Boot to OS". Is that was is happening in your case, or are you mistaking Express Gate for Windows?
Your G73SW should have a hardcopy Express Gate manual included in the box.
G74SX-A1 - stock hardware - BIOS 202 - 2nd Monitor VISIO VF551XVT