If it was that simple I'd do it, but you don't get it. I work for a computer shop. This is for an end user. For a business. He uses Quickbooks (which I'm pretty sure doesn't work in linux outside of a database) and he's computer stupid. I give him linux and he'll have an aneurysm and die.
The computer can handle windows 7. BARELY. It has a P4 with HT and 1GB of RAM. It struggles. The Intel IGP didn't have 7 drivers specifically and doesn't support Aero (who knows what other problems it'll run into). It definitely needs more memory and I'm going to push to put some in, but that's really besides the point. He's not going to be happy with this. I'm not happy with this.