Returns a string containing the drive serial
number (encoded as hex decimal number). This feature is supported by
the fixed drives mostly.
variable = object.SerialNumber
If serial numbers are not supported an empty string is returned.
Applies to: SFDrive object
Windows 95/NT and later
Windows CE 3.0 and later
Pocket PC/Windows Mobile 2003 and later
Windows CE.NET 4 and later