I believe you can create a VirtualBox (basically a VHD) in a different partition, by virtualising the partition instead of creating a VHD.
If you create a standard dual-boot, then no VHD/VirtualBox type software is required. I would install Win7 first, then the Linux distro as the latter usually has better inbuilt options/menus for dual-booting with other OSes. G
There are a veritable ton of guides on how to make a bootable VHD and set it up to boot on your system. Here are a small selection: click here click here click here They largely talk about the beta, but the same thing applies to the Release Candidate, Pre-RTM and likely also the final versions of Windows 7. If you are a MSDN/TechNet subscriber, the later test Pre-RTM builds have been coming out as .WIM images, so making them into VHDs is very easy. You can also find more information looking around the official Windows 7 RC Support Forum located here click here
This thread is now locked and can not be replied to.