I installed Windows 8 as a guest operation system, and I set custom resolutions with this command:

VBoxManage.exe setextradata "Win 8 dev" CustomVideoMode1 1366x768x24

After installing guest additions, it reset all resolutions to the default settings. Even after executing

VBoxManage setextradata global GUI/MaxGuestResolution any

it shows only 4:3 related resolutions in display properties, but I need 1366:768 (which is 16:9 related).

I also tried

VBoxManage controlvm "Win 8 dev" setvideomodehint 1366 768 24

but nothing happened even after guest system reboot.

The resolution appeared (somehow) in the resolutions list after I removed guest additions and installed them again.

But I still need to set the 1920x1080 resolution to the second monitor. Can anyone told me pls, how to do it?


3 Answers 3


This tip from (http://www.mstechpages.com/2011/09/set-custom-resolution-in-virtualbox-for-windows-8/) gave me the hint I needed to finally get it working:

"Did not work for me. I then installed the display driver from the guest extensions which enabled the Host+G shortcut (also worked in fullscreen)"

Here's what I ended up doing:

  1. Install Windows 8.1 on VM
  2. Run the above command: VBoxManage.exe setextradata "GuestName" CustomVideoMode1 1900x1080x32 (several times, actually to add in all the resolutions I wanted)
  3. Install VirtualBox Guest Additions
  4. Extract the drivers from the Guest Additions according to the instructions in the D:\64Bit\Readme.txt a. Open Command Prompt b. Type "D:" c. VBoxWindowsAdditions-amd64 /extract /D=C:\Drivers
  5. Right Click on desktop, choose "Screen Resolution"
  6. Choose "Advanced Settings"
  7. On "Adapter" tab, choose 'Properties'
  8. Choose "Driver" tab
  9. Click "Update Driver" button
  10. Click "Let me pick from a list of device drivers on my comptuer" link.
  11. Choose "Microsoft Basic Display Adapter"
  12. Click Next.
  13. Restart, if prompted.
  14. Back on the Screen Resolution page, choose your new resolution from the ones you added from the command line.

My situation is different from yours but you can try if my solution can solve your problem.

My VirtualBox Guest OS is Win XP which I recently just make it to use a second monitor (1280x1028). My primary display (laptop) is widescreen just like yours which is 1366x768.

At first I am also facing difficulty in setting both my Virtual Screens to fit the exact resolution of both monitors especially my main as there is only 1360x768 as a choice of resolution in the desktop properties setting. My resulting display will then be either messed up in the primary display or the secondary display no matter how I adjust the resolutions.

Later I found out about the Auto-Resize Guest Display function in the View Menu. Thus I will just have to either click it when in Full Screen mode or in Scale Mode (Normal window mode) it will auto adjust the resolution to fit the monitors for me.

However I would say this solution isn't perfect for me though cause my screens will sometimes messed up when I toggle Full Screen Mode and I will have to change the Virtual Screen to different host screen and/or change back depends on whether it works. That might be due to my low video memory but just to share this tip in case you face the same problem.

PS:/ I realise can't post image to illustrate better cause I don't have enough reputation. It did be clearer to find the menu and less wordy as now it is.

I realise I can google an online image to illustrate better, this link shows the View Menu I mentioned.


A little late to the party, but:

The recommended way of handle resolutions in Windows is not to use CustomVideoModes, but instead to install the Guest Additions to the guest and then use the "Auto resize gest display" feature. This works because the Guest additions install a VirtualBox display adapter which supports the resizing. The CustomVideoModes don't seem to get picked up by this display adapter.

This doesn't rule out CustomVideoMode entirely though.

I tend to install a couple of custom video modes to my VMs as I find that in my case the VirtualBox display adapter often crashes/gets disabled by the guest Windows OS. When this happens the display driver falls back to the "Microsoft Basic Display Driver". This driver does pick up CustomVideoModes.

This means that the CustomVideo modes can be used to correctly size the guest display manually and avoid a reboot at an inconvenient moment.

I've waffled on about this at a little more length here.

  • 1
    Sure, the auto resize feature works... unless you want to use a size larger than host monitor (+enable scaling mode), or you want a very specific resolution. The use cases are limited, e.g. high DPI testing on a low DPI machine, but it's certainly something that a quality virtualization package should support.
    – RomanSt
    Commented Nov 8, 2015 at 18:53

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