I can't install 64-bit Ubuntu

[Borneq]

I have Windows 8.1 64 bit. I installed VirtualBox-4.3.14-95030-Win.exe, next i download ubuntu-14.04-desktop-amd64.iso. I can't install it because is 64 bit.

[socratis]

Minimum information needed for assistance

[Borneq]

Virtualbox on Windows has ability to work with Linux guest?

[socratis]

Yes it does. As for the 64-bit, read this: I have a 64bit host, but can't install 64bit guests.

[SeaDude]

I've been struggling with this for a couple of hours now. Just got it to work. Heres my scenario:

Host:
ASUS ROG 750JZ
32GB RAM
Intel i7 4700HQ 64bit
WINDOWS 8.1
Using Hyper-V often


Guest:
Ubuntu 14.04.1 Server 64bit
Want to install on VirtualBox

I tried running "bcdedit /set hypervisorlaunchtype off" in admin terminal then reboot, no go.
I tried going to "Turn on and off Windows Features" and turning off Hyper-V then reboot, no go.
I've gone into UEFI BIOS and turned on and off virtualization and tried installing Ubuntu 64, no go.

Each time I went into VirtualBox, there was no option for Ubuntu 64bit, only 32bit, very frustrating.

Here was my fix and I think it just comes down to order of operations with all the hypervisors and booting up.

• Go to "Turn on and off Windows Features" and uncheck all Hyper-V options
  Reboot
  Go to Virtual Box, try to install your Ubuntu 64bit OS; look for the 64bit option
  If still unavailable, go to UEFI BIOS, (PITA to find: swipe left, settings, change pc settings, update and recovery, recovery, restart now, advanced, etc.) and re-enable virtualization technology.
  Go back to Virtual Box and your Ubuntu 64bit options should be there to select (right click on VM, settings, general, version)

Its hard to tell which order of operations I performed because I was trying all kinds of things, but I"m pretty sure this nailed it.

Hope it helps someone,

SeaDude