Test with a "normal" partition (an image file mounted with VSS):
C:\VSS>dosdev
C: = \Device\HarddiskVolume1 [Fixed]
D: = \Device\HarddiskVolume2 [Fixed]
E: = \Device\CdRom1 [CDRom]
F: = \Device\Harddisk4\DP(1)0-0+f [Removable]
G: = \Device\Harddisk5\DP(1)0-0+10 [Removable]
H: = \Device\Harddisk6\DP(1)0-0+11 [Removable]
I: = \Device\Harddisk7\DP(1)0-0+12 [Removable]
K: = \Device\HarddiskVolume7 [Fixed]
P: = \Device\CdRom0 [CDRom]
U: = \Device\HarddiskVolume3 [Fixed]
V: = \Device\HarddiskVolume4 [Fixed]
W: = \Device\HarddiskVolume5 [Fixed]
X: = \Device\HarddiskVolume6 [Fixed]
C:\VSS>dosdev -d K:
Current definition: K: = \Device\HarddiskVolume7
K: deleted.
C:\VSS>dosdev
C: = \Device\HarddiskVolume1 [Fixed]
D: = \Device\HarddiskVolume2 [Fixed]
E: = \Device\CdRom1 [CDRom]
F: = \Device\Harddisk4\DP(1)0-0+f [Removable]
G: = \Device\Harddisk5\DP(1)0-0+10 [Removable]
H: = \Device\Harddisk6\DP(1)0-0+11 [Removable]
I: = \Device\Harddisk7\DP(1)0-0+12 [Removable]
J: = \Device\HarddiskVolume7 [Fixed]
P: = \Device\CdRom0 [CDRom]
U: = \Device\HarddiskVolume3 [Fixed]
V: = \Device\HarddiskVolume4 [Fixed]
W: = \Device\HarddiskVolume5 [Fixed]
X: = \Device\HarddiskVolume6 [Fixed]
C:\VSS>mountstorpe
C:\VSS>dosdev
C: = \Device\HarddiskVolume1 [Fixed]
D: = \Device\HarddiskVolume2 [Fixed]
E: = \Device\CdRom1 [CDRom]
F: = \Device\Harddisk4\DP(1)0-0+f [Removable]
G: = \Device\Harddisk5\DP(1)0-0+10 [Removable]
H: = \Device\Harddisk6\DP(1)0-0+11 [Removable]
I: = \Device\Harddisk7\DP(1)0-0+12 [Removable]
J: = \Device\HarddiskVolume7 [Fixed]
P: = \Device\CdRom0 [CDRom]
U: = \Device\HarddiskVolume3 [Fixed]
V: = \Device\HarddiskVolume4 [Fixed]
W: = \Device\HarddiskVolume5 [Fixed]
X: = \Device\HarddiskVolume6 [Fixed]
C:\VSS>dosdev -d J:
Current definition: J: = \Device\HarddiskVolume7
J: deleted.
C:\VSS>showdrive
C:\VSS>dosdev
C: = \Device\HarddiskVolume1 [Fixed]
D: = \Device\HarddiskVolume2 [Fixed]
E: = \Device\CdRom1 [CDRom]
F: = \Device\Harddisk4\DP(1)0-0+f [Removable]
G: = \Device\Harddisk5\DP(1)0-0+10 [Removable]
H: = \Device\Harddisk6\DP(1)0-0+11 [Removable]
I: = \Device\Harddisk7\DP(1)0-0+12 [Removable]
J: = \Device\Harddisk3\Partition1 [Fixed]
P: = \Device\CdRom0 [CDRom]
U: = \Device\HarddiskVolume3 [Fixed]
V: = \Device\HarddiskVolume4 [Fixed]
W: = \Device\HarddiskVolume5 [Fixed]
X: = \Device\HarddiskVolume6 [Fixed]
Interesting preliminary difference found:
MountStorPE uses "HardDiskVolume", showdrive uses "Harddiskx\Partitiony"
Wonko