How does a Windows downgrade work?

In the comments to my previous post on Windows downgrades, Paul G asks an interesting question:

Do downgrade options for businesses (or individuals) contain clauses that specify the end of free technical support, or additional fees that apply to the downgrade transaction?

Let’s start with the understanding that downgrade rights apply only when you purchase a new PC with a license for a business edition of Windows.

In this situation, the PC manufacturer is required to provide support for the operating system they pre-install. If you exercise your downgrade rights by installing Windows XP, the manufacturer is not required to provide support for the old OS. You can’t get support from Microsoft, either (except for security-related issues). In practice, this probably isn’t that big a deal. Most of the support you’ll require from an OEM is related to replacing or repairing defective hardware; for garden-variety Windows problems, you can find all the support you need in newsgroups and in Microsoft’s Knowledge Base.

As for additional fees, the answer is no. In fact, the terms of Microsoft’s agreement with PC manufacturers (as outlined in this PDF fact sheet) prohibit them from shipping downgrade media. Legally, they may pre-install an earlier version of Windows for you, but only if they use media supplied by the customer. The license terms in Windows Vista Business and Ultimate specifically relieve the PC manufacturer (and Microsoft) of any obligation to supply media for the earlier version. You are expected to find installation retail, OEM, or volume-license media on your own; in a business environment where you have other PCs with Windows XP installed, you would normally use the install disk from one of those other PCs.

The final hurdle is activating the system. Here’s how Microsoft explains the procedure:

When an end user is using their downgrade rights offered under the License Terms in Windows Vista Business and Ultimate versions and they use both Windows XP media and a product key that was previously activated, they will be unable to activate on-line over the Internet, due to the hardware configuration change when installing on the Vista system. In these cases the end user will be prompted to call the Activation Support Line and explain their circumstances to the Customer Service Representative. Once it is determined that the end user has a valid Vista Business or Ultimate  license, the Customer Service Representative will help them activate their software.

I’ve done this before, and the procedure works exactly as described.

Update: TechARP, which has a pretty good record at providing accurate information on Microsoft’s OEM policies, says Microsoft has recently changed downgrade options that apply to OEMs:

OEMs may now choose to install Windows XP Professional or Windows XP Professional Tablet PC or Windows XP Professional X64 editions instead of Windows Vista Business / Ultimate, provided they meet the following additional requirements :

• Each system must be distributed with a Windows Vista Business or Windows Vista Ultimate Certificate of Authenticity (COA) and must have the appropriate activation markers for both OA (OEM Activation) 2.X and OA 1.0.
• OEMs are required to distribute physical recovery media in the system packaging for the Windows Vista Business or Ultimate version that corresponds to the COA. If the system does not include an optical drive, then the OEM is required to provide a hard drive-based recovery solution for that version of Windows Vista software.

In addition to the required Windows Vista recovery media, OEMs may also choose to provide a recovery solution for the preinstalled version of Windows XP. This may be hard drive-based or on physical recovery media provided in the system packaging or to an End User of such systems upon request.

According to this unconfirmed report, the policy will remain in place for six months after Windows 7 is released.