>>Hex ---- decimal
>>Apply HEX(loDrive.SerialNumber) to see the very same number as in GetDriveInformation
>
>Ok, that is what I thought. But, in that version of the code, I was mixing a volume serial number with a drive serial number. So, they had to be different. But, I have adjusted my class and when verifying the same thing, as you said, a conversion would give me the same thing.

If I understand you correctly, you want to get hard drive serial number, not volume serial number. But both methods that you are using, they return volume serial number. Probably you need to use Win32_PhysicalMedia objects instead of Win32_LogicalDisk.

This may help:
http://www.codeproject.com/KB/cs/hard_disk_serialno.aspx