Hey @Andrew-James I apologize for the delay, here is few steps that can help on this.
On PLABDM02 - Launch the DHCP Manager console seen below and restart the DHCP service:
This is resolves the Error 53 you where getting as the Windows Preinstallation Environment (WinPE) could not get an IP address.
Now for the Access is denied, Error:5 issue, this is most likely due to the fact that when using the net use command you are logging in as the local administrator and not the practicelabs\administrator seen in the screenshot below:
Try this few steps and let me know how it works for you. Member Services is aware of the issue and so is our Practice Labs team. They are working on getting the issue resolved.
Knowledge is a road to be traveled upon, not a destination to be reached~~