VirtualBox Not Recognizing 64 Bit CPU

Question

I recently had to uninstall VirtualBox and reinstall it for various reasons that are unrelated to the purpose of this post. After reinstalling it, I noticed that the option to create a 64 bit virtual machine had disappeared, even though it had worked before.

The version of VirtualBox that I uninstalled and have reinstalled is version 4.3.2 for Windows.

Before anyone suggests to check my BIOS and make sure the virtualization technology is enabled, I assure you that it is.

Since the discovery of this issue, I have updated my BIOS, turned off virtualization, and turned it back on. I am trying to create a 64 bit Ubuntu 13.10 machine, which I had before. What is the problem, and how can I fix it?

Solution

There is a forum post here suggesting that if you have Hyper-V installed and enabled then it may interfere.

If you are not using Hyper-V then I suggest you try uninstalling it. If you go to the Control Panel -> Programs and Features -> Turn Windows features on or off then it should be listed. You should probably restart the computer before re-testing.

Comments

[Keltari]

are you positive you redownloaded the 64 bit version?

[DaveTheMinion]

@Keltari On the downloads page, I only see one download option for Windows. So no, I do not know if I downloaded the correct version, but I have questioned that as well.

[Ramhound]

Have you tried turning it off, there is a bug in a single OEM's BIOS, where turning it on actually turns off actualization.

[DaveTheMinion]

@Ramhound I tried turning it off and turning it back on without fully rebooting the computer, but nothing happened any differently. I assume that everything is okay because it worked in the past. I have an HP ProBook 4540s, if that helps you determine the BIOS that I have.

[Ramhound]

@DavidB - Please read what I said to do. I said to turn it off, leave it off, because the bug is that turning it on actually disables it. I don't remember which OEM it was, I just recall, reading a thread while researching how to enable visualization on my system.

[DaveTheMinion]

@Ramhound Okay, I tried it, and it did not work.There is still no 64 bit option. Take a look at this screenshot to see where I am running into the problem. I think that you and I are not understanding each other.

[Ramhound]

@DavidB - You just confirmed you don't have the motherboard and BIOS with the bug I described. We understand each other perfectly. Lets start with the basics, what CPU exactly do you have, so we can verify your hardware has the capability to run a x64 operating system.

[DaveTheMinion]

@Ramhound I don't know what CPU I have, but I do know that I am running Windows 8.1 Pro 64 bit.

[DaveTheMinion]

I appreciate everyone's help, but James' answer was the one that worked, so it is the one that gets the green check-mark.