screen resolution problem with DVI

I have an HKC 26" monitor, 16:9 aspect ratio. It has VGA, DVI, and HDMI ports. I've been using the VGA and all functioned normally, but now I want to add a second monitor that is only VGA, and as the computer has only one VGA port, I'm trying to set up this monitor to use DVI instead.

The resolution is set at the "recommended" level (1280 x 1024).

I've used the monitor's menu options to define it as a DVI monitor, but the display then comes up at 4:3 aspect ratio, with black bands on either side. I've tried every setting I can find in "Control Panel-->display", most make it worse (generally narrower).

I've gone into Intel's display settings and none fixed it (I believe both ports are on the motherboard; new computer and I haven't been inside).

I've tried every setting in "graphics options-->panel fit" (right click on the desktop)---no help, again most were worse.

I also tried the HDMI; that just brings up an even narrower window with only the wallpaper, no task bar, start menu, etc.

By the way, the second monitor does work concurrently just fine, using the VGA port. I'm running Windows 7.

Please tell me there is just some setting that will magically make my DVI monitor display full-screen!
Thanks---