for the original post, if the license key is for a oem, forget it, it is illegal to install on virtualbox because only retail will be legal to use as virtual machines
This is a grey area, as XP predates virtual machines so there's no specific exclusion against running it that way. I can't see any difference in principle between using dual boot and a virtual machine wrapper as long as it's still on the hardware it was sold for. MS might choose to see it differently because it's a chance to make money, but common sense says he's not trying to use it on a different computer; just use it differently on the same computer. What loss is there to MS in that, especially as they didn't say he couldn't at the time of purchase?
However, whether the VM can be made to look like the hardware enough to allow installation to proceed is the real issue.
WRT activation, my understanding is the hardware information is registered at MS as a hash, so they can't actually tell what combination of MB, disc drives etc produced that hash. The hash can't be changed within four months of a previous activation.
Of course, if installation is successful the dual boot installation should be removed as the licence only allows one copy to be installed.
I think you misinterpreted my post. I wasn't criticising anyone, just trying to stay on the right side of the Digital Millennium Copyright Act, as the forum is a US website and we have seen what can happen.
I'm English. We use irony sometimes.