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Here's a list of possible problems and their solutions that might arise using the virtual machine.
64-bit guest OS list is not displayed
VirtualBox does not present the list of 64 bit OS when creating the virtual machine.
This might be because your own computer is only 32bit. In which case you can't use the virtual machines as they are built as 64-bit.
If you have a 64bit computer, this might be because of settings in Windows 8 or 10 that conflict. Please see this article for more information on the resolution: solution http://www.fixedbyvonnie.com/2014/11/virtualbox-showing-32-bit-guest-versions-64-bit-host-os/#.VvvZBT_VmuA
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