That would be located in your Video control panel.
I have an Nvidia card and if your TV is identified you can make the computer primary , the TV primary, or clone.
I usually have to resize the screen on the TV for it to fit, that's why you're only seeing a background image. The start button and taskbar are off the screen until you resize it.
What we need to know are your hard specs.
Look this over and post back:
In order to troubleshoot your problem we need to know more detailed specs of your system hardware.
1. Go to Start > Run, and type msinfo32. then expand the Components tree and choose a device
2. Go to Control Panel > Device Manager and look for any entry that has a yellow flag beside it.
3. Download
System...