In fact if there is a big issue in Windows, this is it.
The drivers for your PC are at Dell and for the TV it may need you to install a Monitor.inf from the TV maker.
I was running Win XP on an old Dell Optiplex 170L and the TV was working just fine as a monitor. Then I had a problem with the machine and had to reinstall Win XP. It would pick up the TV as a non PnP monitor with only 640 x 480 resolution. I upgraded to Win 7 with the same results. I tried to download and install updated drivers but apparently have not been able to locate the correct one yet. Please help.