External HDD access denied on a Windows 10 Computer

[megavolt]

@Vagabund

Is there a way to undo that?

First check, if it really a linux filesystem:

lsblk --fs

@Vagabund

Two folders appeared on my HDD.
A “system Volume Information” and “$RECYCLE.BIN”.

If that is true, then Windows have or had access to this partition since only Windows creates these folders.