laptop is a Dell inspiron with Intel(R) Core(TM) i5-4210U CPU @ 1.70GHz using intel(r) HD Graphics 4400 , (GOP) Version: 5.0.1037,
Right-click on the desktop and select Graphics Properties. This should start up the Intel HD Graphics Control Panel. Click on Display and then use the Select Display box to select the entry for the TV. You should see a Customize Aspect Ratio selector at the bottom of the settings.
Hope this helps,
I forgot to add: The information above is specific to the older Intel HD Graphics driver packages. If you have a 6th gen or newer processor, you should by now be running the new, DCH-architected versions of the drivers. All driver packages with build numbers (the last number (i.e. after the third dot) in the version string) that are greater than 6443 are DCH-architected. Now, Microsoft has specified that, with the DCH-architected drivers, no Control Panel app is allowed to be connected to right-click Context Menus. Instead, the Control Panel app needs to be re-implemented as a Modern GUI app that is downloaded from the Microsoft App Store. Intel's new app is named Intel Graphics Command Center. This app provides essentially the same capabilities as the old Control Panel app, but is invoked from the Windows 10 Start Menu. It will be automatically downloaded and installed onto your PC the first time you sign in after installing a DCH-architected driver package.
Hope this helps (other folks),