If you google you'll find several references to Microsoft recommending a clean (custom) install
ALWAYS, if you upgrade from XP, RC, and from 32 to 64 bit. MOST of the time if you run your problem through their troubleshooting page it will return the solution = custom install.
Can you provide a link to where Microsoft recommends a clean installation over an upgrade when an in-place upgrade is possible? I haven't found any.
However, since it isn't possible to do an in-place upgrade from XP or a release candidate to Windows 7, or from a 32-bit to a 64-bit operating system, I suppose you
could say that Microsoft "recommends" a clean installation, although it would be more correct to say that it is mandatory since you don't have the choice to do an in-place upgrade. And, naturally, if an in-place upgrade fails then your only option is to do a custom installation. So I suppose you could call that a "recommendation", too, even though, once again, you don't have any alternative.
As for using a "workaround" to custom / clean install to a new harddrive,
Microsoft Says Windows 7 Install Workaround Is Legal Gregg Keizer, Computerworld
Oct 30, 2009 12:00 am
Microsoft today confirmed that users can apply a workaround trick to do a clean install of Windows 7 on a blank hard drive ....that follows the
relaxed rules Microsoft announced in January 2008 for Windows Vista, when it
modified the EULA for Home Premium .
I notice that you don't provide the link to the whole article so that we can read it for ourselves. The link that you do provide pertains only to Windows Vista Home Premium when used in a virtualized environment, which is not a relevant scenario for most users. In addition, when you read the
entire article, you'll notice that neither the author nor the Microsoft spokesman say that an
illegal workaround is legal. Perhaps this will clarify the issue:
Windows 7 upgrade media will do a "clean" installation without reverse-engineering it to allow installation of a version of Windows 7 which is not covered by that media's license. In other words, copying the media, deleting the ei.cfg file, and then burning new media is illegal. It is not necessary to do that to do a "clean" installation. It is only necessary to do that if you want to create media to install a version of Windows 7 for which you don't have a license, which is quite illegal.
To do a clean installation to a blank hard drive using upgrade media, all you need to do is to follow Microsoft's instructions. Install your old licensed operating system first, boot to it. If it is eligible for an in-place upgrade (e.g., if you're going from 64-bit Vista to 64-bit Windows 7), the Windows 7 installer will offer that option. If it is not, your only choice will be to do a "custom" installation, during which you can wipe your hard drive.
Of course, the registry hack and use of
slmgr described here:
is quite legal
if you meet the other licensing requirements. As Eric Ligman, of Microsoft's Worldwide Partner Group has been widely quoted as saying, "'Technically possible' does not always mean legal". While that procedure can be used to install and activate Windows 7 to a computer when you don't own a previous version of Windows that could legally be run on that machine, doing so is illegal. You must own a version of Windows that is legal for that machine in order to install Windows from the upgrade media.
Oh, and one other thing: that hack is completely unnecessary if you follow Microsoft's instructions.
Hopefully, there will be no further mention of methods involving reverse-engineering Microsoft's installation media, such as by deleting the ei.cfg file. They are not legal, and when Microsoft deploys a WGA detector for such tricks,
and you should not bet against it, then you won't be able to get Windows Updates anymore.