Windows 10 Upgrade from Windows 7 Failed

[MelissaW1]

I had upgraded to Parallels V. 11 today and then proceeded to upgrade my windows 7 VM using the method described here:
http://kb.parallels.com/en/122884
I was on the page "ready to install" and after clicking install, I was stopped with this message:
We couldn't install Windows 10
We've set your PC back to the way it was right before you started installing Windows 10
0xC1900101 - 0x20017The installation failed in the SAFE_OS phase with an error during BOOT operation

Is there anyway I can proceed with the upgrade without having to do a clean installation? I prefer to keep my old files.

 

[Manu@Parallels]

Hello MelissaW1,
Please make sure your virtual machine has at least 2GB of RAM assigned. To check virtual machine's RAM please open configuration menu -> Hardware tab -> CPU & Memory. To increase the memory, you would need to shut down your virtual machine.Also, at least 10 Gb free space on virtual hard disk is required.

 

[Andrew@Parallels]

@MelissaW1 - in addition to the solution offered above, please detach most of the USB devices connected to your Mac and let us know if that helped. If not, please either post here or send me a private message. We'll be happy to investigate this and help.