Judy, I also have GeForce card and what I have found is they can be a pain in the posterior.
To get it set up I have to make sure the TV and monitor are on and plugged into the computer before firing up the computer. Then after logging in I have to open the NVidea control panel and set it to use Horizontal span (not clone
). Exit the program and restart the computer. If I don't restart Windows won't show the second monitor in the Settings.
After restart I go to the Windows Settings, right click on second display and activate or attach (depends on what yours lists), then left click on it and make sure it is set to 1024x768, set for Extend and not set as primary. You don't need to restart after this.
If it won't activate then your TV is not being recognized as being connected to the computer. Mine is connected from the computer to my mixer (VocoPro) and then to the TV, so I have to make sure my mixer is powered up as well or the computer will not see the TV.