Microsoft touts that Windows 7 is nimble enough to run on underpowered netbooks. But it also admits that its enticing new XP Mode may not work on netbooks or many other computers of recent vintage.
That people will not be able to run applications designed for XP on Windows 7 by tapping virtualization, as the XP Mode supports, is discouraging news for cash-strapped consumers and small businesses who hoped to upgrade without ditching existing hardware or upgrading their software.
[ InfoWorld's Randall C. Kennedy has called Windows 7's 'XP mode' the right idea, but the wrong technology. | Find out why Microsoft's own App-V would be a better solution to support the XP legacy. | Read InfoWorld's Enterprise Desktop blog and Technology: Windows newsletter. ]
Debuting on the Windows 7 Release Candidate to MSDN and TechNet subscribers today, and the general public on May 5, XP Mode has several strict requirements: 2GB of RAM; Windows 7 Professional, Enterprise, or Ultimate editions; and most limiting, CPU hardware virtualization support.
RAM is inexpensive, and vendors such as Hewlett-Packard have successfully tested netbooks running all versions of Windows 7.
The problem for netbooks is that most run Intel's Atom N270 processor, which lacks Intel's VT hardware virtualization. The same goes for the N270's successor, the N280, which only recently began shipping.
Lack of hardware virtualization support is also a problem for Intel's Atom CPUs for so-called net-top mini-desktop PCs, the 230 and the dual-core 330.
Several members of Intel's Atom Z5 series of CPUs (formerly known as Silverthorne) do support VT. But these are meant for ultra-mobile PCs, and haven't been used on many netbooks yet.
Jeff Price, director of product management for Windows, admitted that the lack of hardware virtualization may also be a stumbling block for many recent notebook and desktop PCs.
Intel and AMD both began offering chips with onboard virtualization more than three years ago. AMD's version is called AMD-V, formerly code-named Pacifica.
Intel Celeron, Pentium Dual-Core, and Pentium M chips all lack VT. Even some Pentium D and Core and Core 2 chips lack VT. Similarly, AMD's Sempron and older Athlon 64 chips also lack AMD-V.
Users can check if their computer supports hardware virtualization by downloading and running a free app, SecurAble.
Without hardware virtualization, users can still run Windows XP virtually using the free Virtual PC 2007 from Microsoft.
Performance won't be as fast as XP Mode, which relies on a newer version of Virtual PC and runs XP at what "feels like native speed to me," Price said, though he warned users not to expect to play 3-D games well in XP Mode.