virtualbox.org

Yesterday i installed a few windows updates on my Windows 7 x64 virtual machine, and now the full screen doesn't work. It's just a black border around the tiny screen. I've tried fully uninstalling the guest additions and the reinstalling them but the problem consists.

Any ideas??

What you are describing is a failed guest additions install. The only other thing that would cause this is to have auto-resize shut off. Look in the view or use the (host+g) toggle to turn auto-resize on/off.

Turned out auto-resize was indeed turned off, I guess it was just a weird coincidence that it happened just after the updates.

Many thanks!