How to change ownership of a file in Windows 10

I have a file that's created by a program, and apparently an interaction with the system and Google Backup & Sync somehow scrambles the owner and permissions of the file. (The owner shows up as either "Unknown" or "Unable to display current owner", depending on where I look at it.)

I need to reclaim ownership of the file.

The standard method (from the File Explorer right click, Properties, Security tab, Advanced, Change Owner) doesn't work because I don't have permission to do that. Basically I need super user access on my own system so I can override what the OS thinks and actually administrate the file.

Anyone got a clue? Rebooting seems to clear the issue but that's a crappy solution. I have a Cygwin shell on this system if that helps. I'd prefer to not have to download any special utilities unless the source is very trustworthy.

Edit The problem re-occured. So far I'm not able to set the owner of the offending files:

C:\Users\Brenden>icacls "C:\Users\Brenden\Google Drive\proj\tempj8\build   \classes\quicktest\AbstractTest.class" /SETOWNER "%username%" /c
C:\Users\Brenden\Google Drive\proj\tempj8\build\classes\quicktest\AbstractTest.class: Access is denied.
Successfully processed 0 files; Failed processing 1 files

C:\Users\Brenden>

This command fails too:

C:\WINDOWS\system32>takeown /F "C:\Users\Brenden\Google Drive\proj\tempj8\build\classes\quicktest\AbstractTest.class"
ERROR: Access is denied.

C:\WINDOWS\system32>