Problem with ATI graphics card

Sorry, I know this belongs in the Apothecary, but honestly, how often do you drop by there? =P

Anyway, the problem is that I'm limited to the lowest screen resolutions: Campaign Map @ 800x600, Battle Map @ 640x480
My graphics card is an ATI Radeon HD 4650 (1GB). I know the problem is only minorish and I believe it's not uncommon for similar graphics cards, there could be a thread about this already, but if there is I haven't found it.

Otherwise, MTW works fine.

Does anyone know how to fix this, if at all possible? Thank you!

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Is the problem that other resolutions don't work, or that the ones you listed the only ones available in the video menu?

Are you using Windows 7?

It's that I cannot select any other option in the video menu. There's only one listed resolution for each setting.
And yes, I am on Windows 7, 64bit.

I'm just thinking aloud/guessing here, but it seems as though the game isn't detecting the full extent of my video card and so defaulting to the lowest possible resolution. It's done it with another game where apparently I only have 128mb of video memory.
I think if that's the case, there's not much to be done. Perhaps I can salvage my old graphics card and select that in the video menu?

I think this has something to do with the windows 7 drivers? Can you dual boot with Windows XP?