VirtualBox also released 4.2.18 last Sept 6, 2013. This must be good, two good products released in the past few days.
Upgrading of VirtualBox didn't work the first time. I have to do a repair to get it to work. So essentially, I have to install it twice.
Installing of Windows 8.1 into VirtualBox was nonevent. But getting guest additions was challenging. I had to read lots of blogs including VirtualBox 4.2.18 release forum discussion topic.
So, how did I get guest addition auto-resize to work? I have to install guest additions *twice*!
This is what was working for me:
- Install guest additions... then reboot.
- After reboot auto-resize was still not working.
- Install guest additions again.... then reboot.
- This time auto-resize worked.