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I am using my first VirtualBox VM in order to run Windows 8 Preview on my Windows 7 machine. It looks like only a few resolutions are available for me to choose. My physical display is 1600x900, so I'd like to be able to set my Windows 8 VM to that in order to have a fullscreen experience. How do I add a 1600x900 to the choices I have in the "Screen Resolution" dialog?

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Seeing similar issues with the released version of Windows 8 and Ubuntu for host – George Mauer Nov 5 '12 at 19:09
Have you by any chance enabled the VirtualBox hardware 3D support ? – harrymc Nov 6 '12 at 18:24
@harrymc yes, everything is enabled for me. – George Mauer Nov 11 '12 at 17:06

You can use VBoxManage setextradata "<vm-name>" "CustomVideoMode1" "1600x900x32" (See the VirtualBox manual for more information).

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I tried this after installing the Guest Additions. The command seemed to work, but I do not see the video mode available in the Screen Resolution dialog. – Patrick Szalapski Jul 22 '12 at 2:55
Ditto. See my (deleted) question… – George Mauer Nov 5 '12 at 19:27
This in conjunction with installing guest additions is the more correct answer as eventually the display mode started working. However it took a few restarts and now it is locked into this exact display mode, it doesn't change with the window size as it did win windows 7. That's a pretty big hassle so I'm still hoping for some insight as far as what is going on. – George Mauer Nov 11 '12 at 17:09
Worked for me with Windows 10 Technical Preview. Thanks! – Dimitre Radoulov Oct 3 '14 at 9:31

This solution worked once for me but now that I have 2 physical monitors it is not working.

You can set the video mode on a running VM by using the following virutalbox command


"c:\Program Files\Oracle\VirtualBox\VBoxManage.exe" controlvm "YOURVMGUESTNAME" setvideomodehint 1920 1200 32


VBoxManage controlvm "YOURVMGUESTNAME" setvideomodehint 1920 1200 32

This setting will take effect immediately and sometimes survive reboot.

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Sounds like all you need to do is install the "Guest Additions" inside your guest OS (which would be Windows 8). It's pretty easy since it's Windows. Just press your host key (probably the right CTRL key) and D. This will mount the Guest Additions .iso as if inserting a CD into a real drive and run the guest additions installer while you're in Windows 8. When done, just reboot the guest (Windows 8) and you should be able to resize to whatever resolution you want. And to go full screen, press the host key (again, probably the right CTRL key) and F to toggle between full screen and a normal window.

There are other ways to do this but that would probably be the easiest. Hope it helps.

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This seemed like a good answer, but I followed your steps and it seems like the Windows 8 display resizes to whatever size window I have. However, the screen blacks out when I go to full-screen and various parts of it flicker on and off when I try to interact. Very unusable. Have you seen this before? I'm using VirtualBox 4.1.18r78361=. – Patrick Szalapski Jul 22 '12 at 2:16
I tried this with 4.2 and latest guest extensions (loaded in both host and guest) and resizing works great. – jdh Nov 8 '12 at 23:07
I'm running the latest of everything (Windows 8 RC on top of Windows 7). Guest additions don't help. I tried reinstalling it, reinstalling VirtualBox, and reinstalling the guest OS. Autoresize doesn't work except occasionally when it feels like. It only picks 4:3 aspect ratios, apparently. Dual monitors aren't detected at all. I don't think they have the kinks worked out for Windows 8. I'll stick with VMware Player until then. – JVimes Sep 15 '13 at 4:25

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