I have a mid-2010 MacBook Pro (has Thunderbolt port) and I would like to use a TV as my monitor. I understand this is possible if you are running OS X but what about Windows?
Apple provides Windows drivers (via Boot Camp) for all aspects of the hardware it is running on, so yes you can.
You'll need a TV with an HDMI input, a Thunderbolt to HDMI adapter and an HDMI cable. After that the Mac, regardless of whether it is running Mac O/S or Windows will see the monitor as a display device and should be able to detect the optimum resolution, allowing you to use it as a monitor.
Note that some HDTVs don't have great definition and displaying the Mac or Windows desktop and apps might result in a blurry result. Only one way to know though, give it a try.