virtualbox.org

Not sure if this is Mac specific or not.

I have a valid, activated Windows 8 Pro VM running well. All guest software seems to work okay too.

Today, I tried using the Windows store to upgrade to Windows 8.1 Pro. This is shown as a free upgrade. But I am stopped immediately, with the attached screen shot. It says:

Sorry, you can't install the update because it isn't supported by your computer's CPU.

The "More info" http://windows.microsoft.com/en-au/wind ... quirements tells me the Processor should be 1 gigahertz (GHz) or faster with support for PAE, NX and SSE2.

Clearly my processor does support Windows 8 and will run Window 8.1 too. I'm guessing the VM is messing with the PAE, NX or SSE2 detection in Windows somehow. The "Runtime Information" tab in my VM session info says "Unrestricted Execution" is enabled - might that be it?

Any suggestions welcome?

Hardware:
17" MacBook Pro (Early 2011)
2.2GHz Intel Core i7 (quad core)
16GB 1600 MHz DDR3

Host Software:
Mac OS X 10.9 Mavericks
VirtualBox 4.3.2 + Extension Pack

VM Configuration:
4096MB RAM
PIIX3 Chipset
I/O APIC enabled
2 Processors
PAE/NX enabled
VT-x/AMD-v enabled
Nested Paging enabled

Guest Software:
Windows 8 Pro
VirtualBox Extensions (4.3.2)
Microsoft Office 2013

Change your guest version (VM Settings, General, Basic, Version) to Windows 8.1.

Thx. This tip did the trick.

Hi,
I have the exact same issue- but not able to change VM Windows 8 version to 8.1 - it is greyed out- Any help will be greatly appreciated

--tried following socartes advice- but it is not an option- am i missing something here- plz help

Naran123 wrote:I have the exact same issue- but not able to change VM Windows 8 version to 8.1 - it is greyed out-

What's your VBox version? Your hardware? Is the guest machine running, paused, saved-state or shutdown? If it is not shutdown properly you cannot change some settings.

Thanks for posting this helped here too. Same problem seeing incompatible CPU when trying to update from Win 8 to 8.1, I had to shut down the VirtualBox image then go to settings->general and change to Win 8.1 64 bit for my machine. While in windows use Winkey+Pause Break to get to your system settings quickly to see which proc type you have (if you see x64 use 64 bit option in VirtualBox to get it working).

Also just to note I'm using VirtualBox in Kubuntu as the host so it seems this "problem" and solution are cross platform.

I had no problem changing the OS type to 8.1 but it still gave the CPU error. I had to check the box for Enable PAE/NX under Settings/System/Processor and then it worked fine.