Put your graphics card back to default settings (i.e. no reduction of brightness, black level, gamma, etc., etc., nothing at all). Then go here:
http://www.simpelfilter.de/en/farbmanagement/monitorcalibration.html
Turn off all the lights in the room, close any doors, shades, etc.
Click on the "Black point" setup test on the left. Now, using your remote control for the Westinghouse LVM-37W3, get into the setup menus and change the "Brightness" level so that you can just bairly read the number "1" in the top left box in the test image. Also make sure you can read the number "2", "3", "4", "5", and "6". You might need to go a little higher then when you first could see the "1", so that you can see the visible brightness differences between the other numbers and the difference appears to be fairly uniform.
Now, click on the "White point" setup test. Again, using your TV remote, now change the "Contrast" level. Push it all the way to the top and then start dropping it down until you can just make out the "1" in the top left box. Same rules apply, as for the "Black point" test, you may need to drop it a couple more notches to get a fairly uniform difference between all the numbers.
Now click on the "Gray point" setup test if your TV supports changing its color temperature. Use this test to make the two sides as similarly colored as you can by changing through your different pre-set or even custom color temperatures. Finally click on the "Gamma calibration" and change the gamma settings. You should also use these test images to properly set the output levels of your different colors (i.e. you can check for red push, green push, or blue push and their contrast levels...). This can get very complicated as any change to one can effect the others especially when you have to deal with the contrast levels of the colors as this will then cause you to need to change the overall color brightness, which then needs to have the other colors set correctly as well otherwise your gray scale goes out of wack.
This is also why there are professional tools to help.