Replying here to clarify stuff.

The issue:
The Windows system assigns monitors IDs. A user cannot change these IDs to what they want.
This is *not* the same as the "Make this my main display"...

Reporting back here.

My problem was that the files I was trying to copy/paste were from another NTFS partition (an USB disk) that had different ACLs.
And the weird stuff is, Win10 seems to check...

Hi there

Looks like I had the same problem, or, something pretty similar.
Yesterday I installed a Win 10 Pro v10240, and when I tried to copy/paste stuff into any AppData/Roaming folder I had an...