Shoutbox

I've just installed Windows 7 on my netbook and it has 2 hard drives, a 4GB one and a 16GB one.....I'd like to combine the two so that it shows as just one 20GB one.

From what I've found through searching it looks like it's possible, but I haven't managed to find anything that makes enough sense for me to follow.  I was wondering if someone could either give me instructions, or point me in the direction of a tutorial that explains it well?

Thanks