Windows 7 - Upgrade version vs clean install version

I need to know if I can use a clean install disk for Windows 7 Ultimate to upgrade from Vista or if I have to use an Upgrade version?

I'm leaning towards buying the clean install disk so that if I should loose the hard drive at some future point I could just clean install Win 7 Ultimate from the disk without having to first install Vista and then upgrade.

Regardless of which type I purchase, am I better off to buy the OEM disk from the machine manufacturer (Toshiba) or just purchase any OEM disk?

Of course, if I want Microsoft support then I need to purchase retail disks.

Thank you.

I suggest the much cheaper upgrade DVD. It will do a clean install, if there is an underlying supporting version of Windows

MS has changed the rules for OEM, they are not for personal use, even if builidng your own computer.

I don't think that is his concern or belief that he would be using an OEM.

And to my recollection, OEM does not really allow you to do an upgrade, you have to do a pure clean install or a repair, but not an upgrade through the OEM version.

Only a Full version will allow you to do a clean install or upgrade (Provided you are at Vista).

While an upgrade will install on older versions of Windows (XP and below), it would do a clean wipe and not a true 'upgrade'.

And as a drawback of this method is that if you have to do a complete reinstall, IE: Fresh new disk and needing to put the OS on, you have to at least put on a previous version of windows on it before you can run the upgrade disk on it.

In all honesty, unless you really want to spend the extra time reinstalling the older OS and then have it redo the OS again from a 'straight' install point of view, the full version of the OS would probably be the better way to go, and probably faster.

Edit - After looking at one of the stickies, looks like you don't need to reinstall the older version of windows, but just have proof you have a qualifying valid Windows License to upgrade. So, if I understand this correctly, so long as you have a genuine, valid product key, you should be able to do a clean reinstall with the upgrade disk without having to do extra. Although from the looks of the chart, you need to have some flavor of XP or Vista to be qualifying for the Upgrade to actually do an install.

Follow Rich's excellent advice.

You can use factory OEM XP/Vista as a qualifying OS to use a Windows 7 Upgrade Version and you can clean install Windows 7 without having the qualifying OS on the HD.

It is explained in detail here with nearly a year of user experience documented: Clean Install with a Upgrade Windows 7 Version