Taking ownership of system files or folders in Windows is not a simple task. This method works in Windows Vista, 7, 8, 8.1, and 10.
In a text editor such as Notepad, copy/paste the following exactly:
Save the file with any name you want, with a .reg extension. Then double-click the saved file and choose Yes to merge the registry file information into the Registry. You will see context menu option named Take Ownership when you right-click file or a folder.
Open This PC to get to This PC in Windows 10, open File Explorer from the taskbar and select This PC in the left pane.
Right click the HDD drive letter that contains your old user files and from the Context Menu select Take Ownership to take ownership of the HDD partition where your old user files located also Take Ownership command will gives full permission to administrators group you should now able to access and copy your old files if any more permission issue use the Take Ownership command from Context Menu to take ownership of the folder that contains your files which you don't have permission to access or copy files from.
Edited by FreeBooter, 22 June 2016 - 09:41 PM.