External HDD & DOS

Diskeeper reports that a large section of my 160 GB EHDD is "Reserved System
Space"
A zero-byte System Volume Information File has somehow lodged there,
creating this reserved space, and Icannot delete it in Windows.
The EHDD contains 7 large Backup folders, plus this lone file.
I have gone to Command and tried various Attrib parameters of *.* -r -h,
in order to access and DEL this file, but sofar haven't struck the right
one.
My old DOS skills have gone - along with my memory - so I would very
much appreciate expert guidance on this problem.

TIA,

Jim.