virtualbox.org

I have my bootcamp partition setup to be bootable in VirtualBox. I have followed the usual steps of creating the raw device access files (the vmdks) for the windows partition. Had it all setup and working great for about 8 months. Now it won't boot! I've tried searching for help with 8.1 boot problems but none of them seem to match my particular situation. Here's what specifically is happening:

- The blue windows logo and spinning dots appear indicating the early boot process is fine.
- The blue windows logo starts to fade out indicating it's trying to bring up the login screen.
- The image freezes and no more visual feedback is given.
- In the virtual box manager, the 'preview' windows starts showing garbage flickering through misaligned colors every second.
- The drive is still be accessed and there is occasional network activity. So I think this is a video problem of some sort.

I CAN boot into safe mode and safe mode with networking. But, I cannot boot into the reduced graphics mode (same behavior when I try this).

My best guess is that some driver got updated (or corrupted) and now the video output just won't work. I used to be a wiz with XP but I'm lost as to how to get more info out of Win 8.1 and clean up the driver situation or to try and backup to an earlier configuration that worked. Even some help trying to get to a log file or a more verbose boot that could help me pin down which driver is screwing the pooch here would be appreciated.

Hardware details:
- Macbook Pro: 15in retina, mid 2014, 2.5GHZ i7 16GB ram, Iris Pro + GeForce GT 750M
- Happy to provide more as needed ... I'm new here and not exactly sure what to throw in here so just ask for something and I'll gladly try and put it up.

Other minimum info:
- Running VirtualBox 4.3.26 r98988
- Host OS: OS X 10.9.5, 16GB Ram
- Guest OS: Win 8.1, Guest Additions Installed, 8GM Ram given
- Log is attached

Seth B.

Ahh, I found the culprit. It's the Guest Additions. I booted into safe mode and uninstalled the guest additions. With those removed it boots file.

I sure do miss my guest additions though!

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The problem seems to be with the WDDM driver that is getting installed. When I re-install guest additions the display will go blank at this point and never comes back. It starts behaving exactly as I described before (black window, preview in the VirtualBox manager is garbage).

I'm thinking this might be related to the following ticket: https://www.virtualbox.org/ticket/12662

It's hard to say. He has a dedicated NVIDIA card like me and the problem is with WDDM in 8.1 like me. His fix does not work on mine though as I cannot update video drivers on a mac host. I can't find one that is exactly this but his screen-caps look a lot like mine.

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I tried rolling back to 4.3.22 and at first it did not work but then I found the following: viewtopic.php?f=2&t=60333
The steps in the last reply did the trick! In particular I had neglected the need to go into the device manager and clear out the old driver.
After this I now have myself back to 4.3.22 with working guest additions.

Seth B.

Hi,

Would you mind outlining, in brief, the steps you took to get your Bootcamp disk working in VirtualBox? I followed the many guides I've found on this forum and elsewhere, but I still get the "No bootable medium found" message.
- I've set the permissions on the disks at /dev
- created the VM raw disk files, trying partitions 4, and 1 and 4
- set the permissions on these vmdk files
- created a VM in VirtualBox, moved the disk controller from SATA to IDE and set the type to ICH6

I've seen these steps above outlined in many places, and haven't found any other steps. I'm running Yosemite (10.10.4) and I don't think there's anything unusual about my setup.

Many thanks for any help.

James