i think the only one that you can use is VMware i used VirtualBox and VirtualPC and they didn't work for me becuase they don't have a good Virual VGA hardware
when you try it and it works please PM me with the details
Install VMware, install windows seven on the virtual mashine, copy rappelz to virtual mashine and it should work bug free. If you haven't got at least 4 GB RAM, you shouldn't even think of it.