First, verify you have up-to-date working backups.
The most direct way to attempt this is with VirtualBox's raw hard disk access feature. It's effectively like swapping the motherboard and video card; the virtual machine's hardware is different than the real hardware. You create a small .vmdk file in Linux that "points" to the real hard disk, do some other mumbo-jumbo, then setup the VM to use that .vmdk as the virtual disk. Boot the VM and see what happens.
As @neurolysis says, it's possible (or probable?) that Windows won't boot correctly. You can then attempt to repair Windows, and if that works, pretty much everything will be where you left it.
Another complication is Windows Activation, if it thinks the hardware has changed "too much". You might then have to call Microsoft, plead your case, then read out and/or type in some forty-digit numbers to make that work. Note that this might also happen if you reinstall Windows from scratch, since your existing serial number is tied to your "old" hardware.