New VM with Windows 7 upgrade install?

I have upgraded to PD8 on a new MacBook Pro (2.7 GHz i7, 16 GB RAM, 512 GB SSD) and migrated my Windows XP VM. I want to upgrade to Windows 7 Home Premium but want to do it with a new, clean installation on a new virtual machine. I actually just tried this but got an error about not being able to install Windows 7 because a valid Windows installation was not found. I don't know if it's because there was not a Windows installation on the new VM (most likely, I'd guess) or because I did have some validation issues with the migrated XP VM. ( I had to validate by phone with a live tech and MS Security Essentials still kept complaining about Windows not being validated. I think I may have just gotten this resolved—prior to the attempted Windows 7 installation). I wouldn't think that the Windows install process on the new VM would know anything about the OS on a different VM. I'm trying to do this with a Windows 7 Home Premium Upgrade (64-bit system install). I would think that there ought to be a valid way to do this with an upgrade DVD and not have to purchase a full version. Do I first have to install my XP full version and then upgrade it?

 

Okay, I found the answer to my question re: installing the Windows 7 upgrade without a previous guest OS installation in the VM. According to the knowledge base (I don't recall the article), it is not possible. Well, with help from a friend who is a pretty good Windows tech, that's not ENTIRELY true. A Windows upgrade will install on a totally clean disk (or, VM) if it can see a previous OS install disk in an attached drive. First of all, because I only have one optical drive, I had to make an .iso image of my Windows 7 upgrade disk (see article ID 4917). Then, I initiated an install using the image file (see article 4729, step 3) and de-selected "Express Install" (same article, step 4). Early in the installation process, I inserted my Windows XP installation disk. Note that, when not doing an express install, Parallels Tools have to be installed manually. Installation proceeded normally. However, it did not validate properly. At this time, I suspect that is because I have made two previous attempts to install from this disk. It might be because it DIDN'T see the XP disk. But, I've got an operating Windows 7 VM and I'll try to resolve the validation issue with Microsoft.