Just to expand on ColGeek's recommendation, with both your monitor and HDTV connected (desktop background on the monitor and Invalid Format on the HDTV), right-click on the monitor's desktop and select, "Screen Resolution". Hopefully, the screen resolution window will appear on the monitor. If so, click on the "Identify" button to verify your monitor is identified as "2". If this is the case, there is an option below titled, "Multiple Displays". Change that drop-down item to "Show Desktop only on 2". This should get you your desktop icons and allow you to make the necessary changes to make your monitor the Primary and your HDTV the secondary displays.