Windows 10 remove System Drive after 1803 upgrade

This is what worked for me:

1. start; CMD right click select Run As Administrator
2. mountvol <Letter of the Drive> /d

 

resource:

https://support.microsoft.com/en-us/help/4337524/windows-10-april-update-new-partition-appears-after-installing

Disable background updates on MAC

 terminal command:

sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate AutomaticDownload -boolean FALSE

https://support.apple.com/en-us/HT207251