Windows installed on 17" MacBook shows bad resolution.
It sounds like the BootCamp drivers haven't been installed within Windows as those are the default software resolutions for graphics cards without drivers. 

The BootCamp drivers can be found on the original set of DVDs that came with the machine, which will be updated to the latest versions once installed in Windows.

You can download BootCamp 3.2 for Windows, and the 3.3 update here, although 3.2 should update once you're online anyway. http://support.apple.com/downloads/#macoscomponents