HP has advised consumer customers not to downgrade new PCs equipped with Windows 8 to the earlier Windows 7 OS, an option which will only be available on enterprise editions of Windows.
The company said that consumer-grade desktop and notebook systems shipped after 26 October - the date Windows 8 launched - will not support the older Windows 7.
"Windows 7 will not be supported on these new platforms, and no drivers, apps, or Windows 7 content will be available through HP," the company said. "If users choose to downgrade their HP consumer desktop or notebook system, HP will continue to support the hardware but if there is an issue where HP diagnostics are required or it is determined that the loaded software or upgrade operating system is causing the issue, HP may suggest returning the system to the original Windows 8 OS."
Downgrade rights - which let customers replace a newer version of Windows with an older edition without paying for two copies - are de rigueur with business-class editions of Windows, and are meant to let companies keep new machines on their preferred OS.
Only Windows 8 Pro comes with downgrade rights; the consumer-standard Windows 8 does not. Windows 8 Pro users can downshift to Windows 7 Professional or Vista Business.
Downgrade rights are available only from OEM copies of Windows, those that are pre-installed by computer manufacturers like HP. As with earlier downgrade rights, the customer is responsible for obtaining the installation media for, say, Windows 7 if he or she wants to downgrade from Windows 8.
HP noted that it will support downgrades on its business-class PCs, implying that it will provide drivers for those machines.
Although HP's for-consumers PCs come standard with Windows 8, customers who have factory-upgraded to Windows 8 Pro - an option available on many machines - acquire downgrade rights. HP charges $70 for the move from Windows 8 to Windows 8 Pro.
HP, like most computer makers, also continues to sell some models with Windows 7 pre-installed. Microsoft's rules allow OEMs to equip PCs with the older OS for up to two years, in other words, until late October 2014.
Do-it-yourself downgrades are more complex with Windows 8, however: Users must first modify the PC's BIOS to boot into what's called "legacy mode." By default, Windows 8 uses UEFI-mode (Unified Extensible Firmware Interface) boot on new PCs to enable some new features, including Secure Boot.
Downgrade rights were a non-factor with Windows 7, which customers generally applauded, but they were newsworthy after Windows Vista's launch in 2007, when many users, frustrated at that edition's problems, mutinied and dropped back to XP.
It's too early to say whether Windows 8 will trigger a Vista-like desire to downgrade, or if customers will take to Windows 8's massive user interface (UI) changes.