cp /dev/hdq /dev/hdx

Where /dev/hdq is your source drive and /dev/hdx is your destination drive.

But you'll lose any additional space that the drive may have, and if it happens to be a few kB smaller, then it won't work "at all". (It'll sorta-kinda work, but you'll be left with a corrupted filesystem and I don't know how Windows will respond to that.)