Microsoft details a workaround for virtual machine bug in Windows 10 build 10049

Microsoft has gone into more detail today about a nasty bug affecting machine virtualization in the recently-released Windows 10 build 10049.

Windows 10 build 10049 was released just yesterday, but it was recommended that those running virtual machines hold off on updating due to a bug with virtualization software Hyper-V. Microsoft went into more detail on exactly what the bug is, and how to work around it in a blog post today:

The bug stops us from being able to correctly register one of our system drivers if you choose to install Hyper-V. It should be noted that if you already have Hyper-V enabled, and then upgrade to 10049 - everything works fine. It is only if you install build 10049 and then enable Hyper-V that you will hit this issue.

If you want to use Project Spartan and Hyper-V on the same system - what you need to do is:

  • Install an earlier version of Windows 10
  • Enable Hyper-V
  • Upgrade to 10049

Alternatively, as noted yesterday, those using virtual machines in the Windows 10 Technical Preview can move to the slow ring and wait for a build with a fix for the Hyper-V bug to roll out there.

Source: Microsoft