Una vez estuve buscando obtener el número de serie del HDD sin usar WMI, y lo encontré. @ El código que encontré y publiqué en StackOverFlow.com funciona muy bien en Windows de 32 bits, tanto XP como Vista. El problema solo comienza cuando intento obtener el número de serie en sistemas operativos de 64 bits (Vista Ultimate 64, específicamente). El código devuelve String.Empty o un espacio todo el tiempo.

¿Alguien tiene una idea de cómo solucionar esto?

EDITAR

Utilicé las herramientas que Dave Cluderay sugirió, con resultados interesantes:

Aquí está la salida de DiskId32, en Windows XP SP2 de 32 bits:

To get all details use "diskid32 /d"
Trying to read the drive IDs using physical access with admin rights
Drive 0 - Primary Controller -  - Master drive
Drive Model Number________________: [MAXTOR STM3160215AS]
Drive Serial Number_______________: [            6RA26XK3]
Drive Controller Revision Number__: [3.AAD]
Controller Buffer Size on Drive___: 2097152 bytes
Drive Type________________________: Fixed
Drive Size________________________: 160041885696 bytes

Trying to read the drive IDs using the SCSI back door

Drive 4 - Tertiary Controller -  - Master drive
Drive Model Number________________: [MAXTOR STM3160215AS]
Drive Serial Number_______________: [            6RA26XK3]
Drive Controller Revision Number__: [3.AAD]
Controller Buffer Size on Drive___: 2097152 bytes
Drive Type________________________: Fixed
Drive Size________________________: 160041885696 bytes

Trying to read the drive IDs using physical access with zero rights

**** STORAGE_DEVICE_DESCRIPTOR for drive 0 ****
Vendor Id = []
Product Id = [MAXTOR STM3160215AS]
Product Revision = [3.AAD]
Serial Number = []

**** DISK_GEOMETRY_EX for drive 0 ****
Disk is fixed
DiskSize = 160041885696

Trying to read the drive IDs using Smart

Drive 0 - Primary Controller -  - Master drive

Drive Model Number________________: [MAXTOR STM3160215AS]
Drive Serial Number_______________: [            6RA26XK3]
Drive Controller Revision Number__: [3.AAD]
Controller Buffer Size on Drive___: 2097152 bytes
Drive Type________________________: Fixed
Drive Size________________________: 160041885696 bytes

Hard Drive Serial Number__________:             6RA26XK3

Hard Drive Model Number___________: MAXTOR STM3160215AS

Y DiskId32 se ejecuta en Windows Vista Ultimate de 64 bits:

To get all details use "diskid32 /d"

Trying to read the drive IDs using physical access with admin rights

Trying to read the drive IDs using the SCSI back door

Trying to read the drive IDs using physical access with zero rights

**** STORAGE_DEVICE_DESCRIPTOR for drive 0 ****
Vendor Id = [MAXTOR S]
Product Id = [TM3160215AS]
Product Revision = [3.AA]
Serial Number = []

**** DISK_GEOMETRY_EX for drive 0 ****
Disk is fixed
DiskSize = 160041885696

Trying to read the drive IDs using Smart

Hard Drive Serial Number__________:

Hard Drive Model Number___________:

Observe cuánto menor es la información en Vista y cómo no se devuelve el número de serie. También la otra herramienta, EnumDisk, se refiere a mis discos duros en Vista como "SCSI" en lugar de "ATA" en Windows XP.

¿Algunas ideas

EDIT 2:

Estoy publicando los resultados de EnumDisks:

En Windows XP SP2 de 32 bits:

Properties for Device 1

Device ID: IDE\DiskMAXTOR_STM3160215AS_____________________3.AAD___

Adapter Properties
------------------
Bus Type       : ATA
Max. Tr. Length: 0x20000
Max. Phy. Pages: 0xffffffff
Alignment Mask : 0x1

Device Properties
-----------------
Device Type     : Direct Access Device (0x0)
Removable Media : No
Product ID      : MAXTOR STM3160215AS
Product Revision: 3.AAD

Inquiry Data from Pass Through
------------------------------
Device Type: Direct Access Device (0x0)
Vendor ID  : MAXTOR S
Product ID : TM3160215AS
Product Rev: 3.AA
Vendor Str :



***  End of Device List  ***

Y en Vista 64 Ultimate:

Properties for Device 1

Device ID: SCSI\DiskMAXTOR_STM3160215AS_____3.AA

Adapter Properties
------------------
Bus Type       : FIBRE
Max. Tr. Length: 0x20000
Max. Phy. Pages: 0x11
Alignment Mask : 0x0

Devic,e Properties
-----------------
Device Type     : Direct Access Device (0x0)
Removable Media : No
Vendor ID       : MAXTOR S
Product ID      : TM3160215AS
Product Revision: 3.AA

Inquiry Data from Pass Through
------------------------------
Device Type: Direct Access Device (0x0)
Vendor ID  : MAXTOR S
Product ID : TM3160215AS
Product Rev: 3.AA
Vendor Str :



***  End of Device List  ***