After KB5101650 I now have a "these files might be harmful" for USB HDD

I KNEW it would cause a problem somewhere!
My WD 10TB (shows as G:\ ) is plugged into a USB 3 port, not networked or mapped. I don't have a local network setup at all, just wifi.
Since the update, if I try to copy ANY file from the drive to say the desktop I get the harmful files dialogue box.
I can copy TO the WD or "Send to" FROM it, no problem.
Copy a file from desktop to it ok, but harmful files box copying the same file back.
Set local intranet sites to 192.168.1.* to allow anything on the local network. Played with Trusted sites too, set to low risk. No difference.
Tried group policy - User Configuration > Administrative Templates > Windows Components > Internet Explorer > Internet Control Panel > Security Page
Did all as suggested here: Disable These files might be harmful to your computer warning in Windows
No difference.
Had to undo GPOL settings as I wound up with control panel internet options sites settings greyed out.
Deleted 192.168.1.* site.
One suggestion online was to change drive letter. I changed it from G: to K: and that fixed it!
Changed it back to G: and problem comes back.
Not sure if or how G:\ can be added to a trusted site list as it's not a network drive.
Any ideas?

Per co-pilot, Windows stores zone mappings in the registry. One of these keys almost certainly contains a stale entry for G::

HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Drives

and/or

HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2

Look for any subkeys referencing G:. Delete them, reboot, and Windows will rebuild clean entries.

This removes the incorrect “network zone” classification and stops the warning even if you switch the drive back to G:.

I'll try that, but I also noticed that copying files from G: to C:\ root does NOT cause a problem, but copying to any folder on C:\ (inc desktop) does.
Weird?

Maybe this is your problem and solve it :


EDIT : Just saw the fix is in latest preview update

Sounds like it, but my system is not on a network so DFS doesn't apply.
However it is Microsludge, so the final update will probably fix it anyway.

Per co-pilot, Windows stores zone mappings in the registry. One of these keys almost certainly contains a stale entry for G::

HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Drives

and/or

HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2

Click to expand...

Went through all the keys - nothing...

UPDATE: FIXED!?
Ok, it seems to have fixed itself today. I rebooted and tried it 4 times and it's gone.
Today the pc updated Acrobat reader, Visual C++, Edge, Office and OneNote.
Looks like some component of one of them was the issue!
Go figure.

UPDATE: NOT fixed, back again today!
However, using Ctrl+C and Ctrl+v works fine, so it' s dragging issue...

Changed drive letter and it's been fine since.
Hopefully it'll stay that way.
Obviously the old drive was flagged somehow, somewhere...

Just an update - drive letter changed for 3 weeks now and no issue.
Just changed it back to the original letter, rebooted and still fine.
Gotta love Microsludge.