I’ve read lots of discussion of XP Mode over the past 10 days (a tip of the hat to Rafael Rivera and Paul Thurrott for their excellent coverage so far, including Rafael’s breakdown of Windows XP Mode Internals, part 1 and part 2.). But I’ve only seen a few passing mentions of a possible stumbling block that will affect many people who try out Windows 7.
If you download the Windows 7 Release Candidate, as many people will do when it becomes available this week, you can also download a beta version of Windows Virtual PC and a fully licensed virtual machine running Windows XP SP3 to go along with it. But will you be able to install XP Mode?
That depends on whether your CPU supports it. Don’t assume that you can use this feature because you have a new PC with a fast, powerful processor. Windows Virtual PC, which powers XP Mode, requires hardware virtualization. In the case of Intel CPUs, that means the CPU has to include a feature called Intel VT.
If your PC is powered by a new quad-core Q8400, you can’t run Windows Virtual PC. An E6600 supports VT, while an E7400 doesn’t. But an E8200 includes VT support.
The Intel product matrix is downright baffling, which is why I went to Intel’s website and spent a couple hours putting together information about which CPUs in which families support hardware virtualization. You’ll find the detailed explanation, along with separate charts for desktop and mobile CPUs from Intel, here:
How many Intel CPUs will fail the XP Mode test in Windows 7?
If you’re thinking of buying a new PC with Windows 7 in mind, you’ll definitely want to incorporate this data into your research.
Ed Bott 
A great quick way to see if your current processor can support hardware virtualization is with GRC’s SecurAble:
http://www.grc.com/securable.htm
Hey Ed,
I first heard you on Computer America a few weeks ago, and simply loved what you had to say there, and so I tracked down your website and subscribed to this blog. I have to say, you continue to impress. Due to time constraints, you are among a very select few RSS feeds I subscribe to.
This article was such useful information, that I HAD to actually come to the blog itself so I could leave this comment.
Kudos to you for this excellent post (and thanks for distilling your research effort) and related resources. You are a real asset for the Windows community… down to earth and so far, I pretty much agree with you completely (though that is no requirement by any stretch).
Thanks – You’re the man!
One other wrinkle is that many (most) OEM’s ship with VT tech disabled in BIOS. Even if your CPU supports it does your BIOS?
Agreed, Brian, and I put that note on each of the tables.
Greg, that’s great if you already own a PC. The manual lookup is good if you’re researching a potential purchase and can’t actually run your own software on it yet.
Alan, thanks for the kind words!
Will 64-bit Windows 7 support Windows XP 32-bit via the XP mode? I have seen numerous questions on the links you mention, but no definitive answer. The sweet spot on hardware seems to be 64-bit these days, but the prospect of checking all my applications for compatibility with Vista 64-bit is daunting. A 32-bit XP mode on 64-bit Windows 7 would be a real winner.
David, Windows Virtual PC will ONLY run 32-bit operating systems. Although I haven’t tried it yet, I am 100% confident that the two XP Mode VM packages are identical, with the difference being what they do with Virtual PC on the host system. It’s a 64- or 32-bit Virtual PC program, but the XP virtual machine is always 32-bit.
I’ll be testnig shortly and will report back if I see anything different, but I don’t expect to.
Intel’s recent Product Change Notification (PCN) seems to be related to this issue. Their April 15, 2009 notice, http://content.intel.pcnalert.com/dm/d.aspx/A3E94F65-56CE-4E4D-B272-2C59B2F90B0B/PCN109337-00.pdf, details the addition of the VT feature to a range of popular desktop processors. It appears the by the time Windows 7 RTM gets released, most new desktop PCs will be able to run XP Mode. I expect a similar PCN regarding mobile processors before too long.
Norm, thanks for that link. I actually covered this in an update in the ZDNet post. It’s only five specific processor SKUs, which might be the more popular ones but are certainly not indicative of the entire market.
Pretty simple for AMD, in contrast. As the challenger, they give you stuff “for free” because they don’t get to do as much market segmentation. Basically, unless you’re buying a Sempron or some uncommon backward-compatibility AMD chip, every modern AMD chip has hardware virtualization.
Virtual PC has long supported 32-bit guests only, whether the host was 32-bit or 64-bit. Want 64-bit guests? Go to VMWare or Hyper-V.
Also, Windows XP x64 was a niche operating system, for CAD workstations and the like. It even used a different kernel than 32-bit XP — the Server 2003 kernel — so you’d occasionally find software that misdetected it as Server 2003 and refused to run. XP Mode is intended for broad compatibility, which means 32-bit XP.
Thanks for this report Ed. I have an interest in 7’s XP Mode and was pleased to see my HP has the correct processor. Checking the BIOS, I found it did have a setting to enable vitualization. Interestingly, the text that appears with that item on the BIOS menu says HP recommends not enabling this feature. Now I am curious, why would HP recommend not using a feature they specifically included in the computer they sold me?
randall, there was a big scare about rootkits being able to hide themselves more thoroughly from the OS by running as a hypervisor. Search for ‘blue pill’.
The threat is mitigated by the usual anti-rootkit blocks: anti-virus/anti-malware programs, programs must be running with administrator rights to modify boot records of hard disks, and User Account Control should prevent many programs running privileged even if you’re logged in as a privileged user. There are also suggestions that Blue Pill is not as undetectable as was claimed.
I suspect this is an issue of unsynchronized planning; support for non-hypervisor virtualization was dropped for Windows Server 2008 Hyper-V, which I think Windows Virtual PC 7 is a development of. It was reasonable to expect new servers to be bought for new Hyper-V, and most server processors include VT. It’s not reasonable to require VT for desktop virtualization.
#10, Randall: It still may not work.
Even though I have a CPU that supports VT (Intel Core 2 duo e6420) and virtualization is turned on in the latest BIOS (Dell Inspiron 530, BIOS v 1.0.18), the Virtual Windows XP will not start (or install) because the “hardware-assisted virtualization is disabled.” I get the same error from Virtual Windows XP on 64bit Windows 7. Gibson’s Securable says virtualization is “Locked Off” in 32bit Vista and 32b Windows 7 RC and “Locked On” in 64bit Windows 7.
(Yes, there are 3 OSs on this machine, Vista 32 and both verisons of Win7.)
The older version of Microsoft’s Virtual PC (v2?) runs fine on Vista, so I assume it doesn’t use the CPU VT extensions. I hope this is just a beta thing.
Have a Q6600 processor in my Dell Inspiron 530, BIOS v 1.0.18) – like #12 and am having the same issue. Was really looking forward to trying that out although I do have VMWare and VirtualBox VM’s I have used before. I haven’t tried them yet with the new RC.
I suggest that anyone who has a PC in which the OEM BIOS disables virtualization and does not provide an option to turn it on should pester their OEM for a BIOS update. Perhaps if enough do they will respond.
Actually the Q8400 have VT, as it was announced at the same time Intel added VT to the Q8300.
I have an Intel E8400 CPU with VT. I have installed the Virtual XP but it will not run. I have enabled VT in the bios also. Any suggestions?
Have you tried the newsgroups? They have much more experience with a broad range of configurations than I do. I don’t have a link right now, sorry. You might check at the Virtual PC download page.
i have been running virtual xp on w7.7100 for about a week with no problems, however this morning when starting up vm i got the message that virtualisation is not enabled in BIOS. i checked and my bios reads virtual machine enabled (did intel virtualisation test, ran ok) so i uninstalled virtual xp and attempted to reinstall via download from ms, and, i still get the same message, vm not enabled in BIOS. any ideas ?
regards
ollyc12