With your laptop connected to your Receiver and the receiver connected to an HDTV also via HDMI. Change your receiver's input to match the input the laptop is connected to (Video 1, Video2, AUX, etc...).
On your laptop, right-click anywhere on the desktop. If you see an option like "NVidia Control Panel" or "AMD Catalyst Control Center", select that option. If you don't see either of those options, select, "Screen Resolution".
If you selected NVidia Control Panel, on the right side, under the "Display" tree, you should see an option for "Set Up Multiple Displays". Select "Set up multiple displays". In box one, you should see a list of all connected displays with the currently enabled displays identified with a numbered black box to the right or the display name.
To enable a secondary screen, check the box which should be labelled, possible as simple as "TV" or perhaps as the model number of your receiver. In the view below, a second display should appear. If you are content with the orientation, click the apply button. Otherwise, you can click on one of the displays in section 2 and move it in conjunction with it's location to the other display. When done, click Apply.
You should then be given the option to save this option and you should now also see either a clone of your laptop display (Clone Mode) or at the very least, a copy of your laptop display's desktop background (Extended Mode). Right-click on either display in section 2 to change between clone and extended mode.
If you selected AMD Catalyst Control Center (or AMD Vision Engine) or if you have neither of the above options and select Screen Resolution, the process is nearly identical.
For AMD Catalyst Control Center, enabling a second display is under Desktop Management --> Creating and Arranging Desktops.
For Intel Screen Resolutions, click the secondary display and then from the Multiple Displays Drop down, select duplicate desktop (Clone) or extend Desktop to this display.
Regardless of which option you have available to you, you should now have your laptop screen on your HDTV.
-Wolf sends