virtualbox.org

I am using Virtualbox 4.2.16 on a Windows 8 Professional laptop. My purpose with VB is that I setup VM as demo machines.

The virtual machine I am currently using is changing the settings of the OS type when I reboot my laptop. The VM is Windows 2008 Server 64 bit and have the acceleration setup to use 4 processors. When I reboot the laptop, the settings change to set the windows type to Windows XP and I do not have the options for the Windows server.

In order to correct the problem I must shutdown, go to the bios and disable the Intel Virtualization, reboot. Then shut down, go back to the Bios, enable the Intel Virtualization and reboot. After doing this the O/S types are now available and I can select the correct OS type and start the VM.

Well that's a new one. I can't think of anything VirtualBox that would cause this issue. Did you do anything fancy with the install, change permissions, or file locations?

Wild guess - something else is sometimes grabbing the VT-x feature. When you start VirtualBox it notices that 64bit guests are not allowed and so removes those from the templates list.

Given the Windows 8 host, Hyper-v would be the obvious suspect.