Setup: You want to copy all the permissions from one file to another with PowerShell
Solution:
Move to the folder of the source file
$Permissions=GET-ACL SourceFile.ext
Move to the folder of the destination file:
SET-ACL DestFile.ext –aclobject $Permissions
This method is very useful for copying the permissions of .vhd files after you move/copy them between different folders/virtual machines.
Before attaching a vhd file to a Hyper-V virtual machine use these commands to copy the permissions from existing vhd to new vhd.