[quote name='Richard Longfellow']Wait...are you playing on TV or a PC monitor? If it's a TV set, then you may have your aspect ratio set wrong on the TV. Is the game retaining the widescreen settings after you exit the menu? Does the picture look vertically stretched in a 4:3 frame on your TV? If so, then it has to be your TVs settings. If it's a Sony, you'll want it on "full", which will autodetect the aspect ratio signal sent by the video card. Other brands have their own terminology.[/quote]
Yeah, I have my computer hooked up to my HDTV. It's not stretched. The screen is autodetecting everything except these three games.
Also, I just uninstalled Portal, then reinstalled it, and it's still saying "Mode not supported". Why did it save the configuration? I deleted everything
[quote name='level1online']Are you using a nvidia card?
Go into the Nvidia Control Panel, in Display category change Flat Panel Scaling to "Do not scale"

[/quote]
Mine doesn't have the "Change flat panel scaling" option....
[quote name='Richard Longfellow']One more thought..."mode not supported" might be an unsupported resolution. Try reducing your game resolution down to the maximum supported by your set.[/quote]
That's what I'm currently trying to do, but I can't get into the game to change it because, every time I load up the game..."Mode not supported"