I am trying to use my tv as a computer monitor and I am unable to get a good screen resolution. I curretly have the computer/tv connected via HDMI and only the middle half of the screen shows picture. When I right clik on the desktop and select screen resolution it will not allow me to adjust. How can I get the content to show on the entire tv screen? TV is model Pannasonic PT-50LCX64 and my computer does not have a dedicated graphic card, rather it uses the HD3000 graphics built into the Intel CPU, if this matters.