How to Fix: Virtualbox: Can't Change Settings, Can't Click OK

Dennis Faas's picture

Infopackets Reader Steve G. writes:

" Dear Dennis,

I run a small business and we use Virtualbox to control our virtual server (Windows Server 2016). We had a hardware problem with the hypervisor machine, forcing us to copy the virtual server onto another machine temporarily for a week. Now that we're done fixing the hypervisor machine, it's time to move the virtual server back over. The problem is that I get an error message from Virtualbox stating that "Cannot start virtual machine because the following physical network interfaces were not found ... (etc)" It then gives the option to "Change Network Settings", "Copy", and "Close VM". If I try and change network settings in Virtualbox, a new window appears but I can't make any adjustments. Also, I can't click OK in Virtualbox. I've tried clicking other options and the "OK" button is ghosted. I am completely at a loss and none of the pages I've come across tell me how to get around this problem. Can you PLEASE help? "

My response:

I asked Steve if he would like me to connect to his machine to have a closer look using my remote desktop support service, and he agreed.

Below I will discuss my findings.

How to Fix: Virtualbox: Can't Change Settings, Can't Click OK

Based on my research, this issue is compounded. You will need to ensure that:

a) virtualization (Intel VT-x and VT-d / AMD SMS) is enabled on the hypervisor

b) NX is enabled on the hypervisor

c) Hyper-V is *DEFINITELY* disabled (even if it says it's not enabled!) on the hypervisor

d) create a new hardware MAC address on the virtual machine's network adapter

I'll explain more in detail below.

Virtualbox: How to Check if VT-x and NX Are Enabled

The easiest way to check if both virtualization and NX-bit is enabled on the hypervisor is to use a third party freeware utility called "Securable" by Gibson Research. When you execute it, it should say "64 maximum length", "Yes / hardware D.E.P.", and "Yes / hardware virtualization". Click here for an example image showing all 3 options enabled.

If "D.E.P." or "hardware virtualization" is not enabled, you will have to enable it in the computer's BIOS. Depending on your motherboard's BIOS, the virtualization might be called "VT-x" (and "VT-d") for Intel, or "SMS" for AMD. Please consult your motherboard manual on how to do this, or contact me for additional 1-on-1 support using my remote support service.

Virtualbox: Disable Hyper-V (Even if it says it's Not Enabled!)

Hyper-V causes a conflict with Virtualbox and prevents you from being able to click "OK". This conflict can exist even if Hyper-V says it's not enabled, especially in Windows 10. This is a huge gotcha as I've discovered in recent years. To fix this, you will need to enable Hyper-V and then disable Hyper-V it to correctly "clear" the issue.

To do so:

  1. Click Start, then type in "control" (no quotes); wait for "Control Panel" to appear, then click it.
  2. The "Control Panel" window will appear; click "View by: " and select "Large icons".
  3. Next, click "Programs and Features"; at the top left, select "Turn Windows Features on or off".
  4. A new window will appear; scroll down and look for "Hyper-v" and place a check mark beside it to "enable" it. You will have to reboot the machine to finalize the changes. I suggest you press CTRL-D on the keyboard now to bookmark this page and come back after the reboot.
  5. After reboot, do the same procedure as mentioned in the above paragraph, except this time remove the check mark to "disable" Hyper-V. You will likely need to reboot again and come back to this page.

At this point, the virtual machine should start, and you should be able to click the "OK" button if attempting to make adjustments and/or start 64-bit guests in Virtualbox.

Fix: Virtualbox Physical Network Interfaces Not Found

If you start the virtual machine and receive an error that "Cannot start virtual machine because the following physical network interfaces were not found ... (etc)" then you will need to make one final adjustment which changes that virtual machine's MAC address and/or select the appropriate network interface on the hypervisor.

To fix this issue:

  1. Launch Virtualbox, then select the virtual machine that is having the issue.
  2. Next, click the "Machine" menu at the top, and then select "Settings".
  3. The virtual machine settings window will now be displayed. Click the "Network" menu on the right, and ensure that the network adapter "Name:" pull down menu has the correct network adapter selected.
  4. Following that, click the "Advanced" option (a purple arrow) to expose other options. Under the "Mac address" selection, click the refresh arrow to input a new MAC address, then click "OK".

You should now be able to start the virtual machine.


Additional 1-on-1 Support: From Dennis

If all of this is over your head, or if you need help getting your virtual machine running (or anything to do with virtual machines for that matter) - you are welcome to contact me for additional 1-on-1 support, where I can connect to your machine and fix it for you. Simply contact me, briefly describing the issue, and I will get back to you as soon as possible.

About the author: Dennis Faas

Dennis Faas is the owner and operator of With over 30 years of computing experience, Dennis' areas of expertise are a broad range and include PC hardware, Microsoft Windows, Linux, network administration, and virtualization. Dennis holds a Bachelors degree in Computer Science (1999) and has authored 6 books on the topics of MS Windows and PC Security. If you like the advice you received on this page, please up-vote / Like this page and share it with friends. For technical support inquiries, Dennis can be reached via Live chat online this site using the Zopim Chat service (currently located at the bottom left of the screen); optionally, you can contact Dennis through the website contact form.

Rate this article: 
Average: 2.7 (7 votes)