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I'm using Vista 32 bit on my home box. I have Microsoft Virtual PC 2007 installed. I also have Windows Server 2008 on a DVD. Not Windows Server 2008 R2.

When I try installing Server 2008 on a virtual machine, I get a message telling me my CPU is not compatible with 64 bit mode and can't load a 64 bit application (can't remember the exact message.)

My CPU is an Intel quad core from 2008, which I believe can handle 64 bit apps. What's more, why would I get this message if I'm installing 32 bit Windows Server 2008?

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migrated from Aug 18 '11 at 7:07

This question came from our site for system and network administrators.

Last-first: You wouldn't get that message with a 32-bit OS. Let's say "shouldn't".

And a processor in 32-bit mode can't virtualize a 64-bit OS.

And Virtual PC can't do 64-bit guests even with the 64-bit version.

And... Bottom line, install a 64-bit OS for the host, get a 64-bit Virtualization program other than Virtual PC, and it'll all work.

And this might be a better question for SuperUser.

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I'm not sure what you're asking. Your question title and question itself don't really agree do they?

Windows 2008 server came in both 64 and 32 bit versions. If you're getting that message it would suggest you have the 64 bit version.

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You're right about the title-- sorry for the confusion. I had written it earlier, when I tried to install Windows 2008 R2 and failed. Instead of posting I downloaded and tried installing Windows 2008 32 bit, and still got the 64 bit message. So I changed my post but forgot the title. – larryq Aug 19 '11 at 3:20

I see you've got it to install.

Just to clarify things:

                    | 32bit Guest | 64bit guest 
32bit Host          | Yes         | No
64bit Host (No VTx) | Yes         | No
64bit Host (VTx)    | Yes         | Yes

As you can see, VT extensions are needed to run 64bit guests.

Also, the virtualisation software must support running 64bit guests. Does Virtual PC 2007 support this? I know that Virtual Box does.

One thing I am not entirely certain about is if you have a 64bit VT enabled processor and have installed a 32bit OS onto it. Can you run a 64bit guest? Perhaps someone could answer that for me. I haven't tried it but I think I recall reading that it was not possible somewhere. In any case, running 64bit requires VTx (or the AMD equivalent).

There are quite a number of Intel processors out there that are 64bit, but do not have the virtualization extensions. These can run Windows Server 2008 R2, but not as a virtualized guest. To do that you'll have to install Windows Server 2008 release 1.

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Thanks for this Matt. I don't know what Virtual PC 2007 supports either regarding 64 bit guests either, and I didn't have any idea about VT extensions on Intel processors-- shows how green I am in this field currently. – larryq Aug 19 '11 at 18:11
Don't worry. It took me a while to figure this out. A table like the above didn't exist when I went looking a year or two ago. – Matt H Aug 21 '11 at 22:59

Turns out this was operator error-- my virtual PC had pointed its CD rom device to the original Win 2008 R2 ISO I had downloaded, when I thought I had repointed it to the DVD I had burned of regular, 32 bit Win 2008. Once I corrected that the install went smoothly. Sorry for the trouble everyone.

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