Two drives with the same volume serial number

I just noticed that two of my hard drives (one is the boot drive, and both are internal SATA drives that are always running when Windows (Win7 64) is) have the same volume serial number. I'm talking about the 8 hex digits assigned by Windows when a primary partition is formatted as a drive, not the hardware serial number from the manufacturer. The two volumes are each the first primary partition of separate physical drives.

The odds of it happening by chance are miniscule, so I guess this must have happened when I imaged one to the other. That last happened over a year ago, and I haven't had any problems, so apparently it's not a fatal error. But still, it seems like if Windows can't tell my boot drive from my data drive, an accident is waiting to happen.

Should I try to fix this, or is the fact that they are on different physical drives mean that there is no way Windows can get confused?

CAN I fix this? I'm comfortable editing the registry, and I have a sector editor to edit data on the disk directly, but I can't find the serial number on the disk, plus I'm worried that I may break something if I change the serial of my data drive without going through Windows.

Also, how can I make sure this doesn't happen again when doing an image copy? I'm not sure whether this happened using Acronis or Paragon.

Any tips greatly appreciated.

Windows uses another ID, called the disk signature, to uniquely identify physical disk drives. It is these signatures that cannot collide. Volume Serial Numbers do not have to be unique, though I believe software uses them for licensing purposes, so it is a good idea to keep the VSN the same when cloning or restoring from an image - there the assumption is made that the old drive will be discarded or reformatted and given a different VSN. I don't think having duplicate VSN has any harmful effects.

TVeblen said:

You can see your Volume Serial Numbers by going to Start > All Programs > Accessories > System Tools > System Information > Components > Storage > Drives.

Correct, and the two drives have the same VSN numbers, but are on different physical hard drives. The VSNs of my other drives (I have three physical drives which are each partitioned to have three or four logical drives) are all unique.

GeneO said:

Windows uses another ID, called the disk signature, to uniquely identify physical disk drives. It is these signatures that cannot collide.

I assume you are talking about the four bytes at offset x1B8 in the MBR. Those are unique for me.

Volume Serial Numbers do not have to be unique, though I believe software uses them for licensing purposes, so it is a good idea to keep the VSN the same when cloning or restoring from an image - there the assumption is made that the old drive will be discarded or reformatted and given a different VSN. I don't think having duplicate VSN has any harmful effects.

I think you must be right, because I looked through the old reports from my disk cataloger, and I've had several duplicate VSNs in the past, probably going back several years, and no problems that I'm aware of. So I guess I won't worry about this until the next time I format or image a drive.

Thanks to everyone for the responses.

brocks said:

GeneO said:

Windows uses another ID, called the disk signature, to uniquely identify physical disk drives. It is these signatures that cannot collide.

I assume you are talking about the four bytes at offset x1B8 in the MBR. Those are unique for me.

Volume Serial Numbers do not have to be unique, though I believe software uses them for licensing purposes, so it is a good idea to keep the VSN the same when cloning or restoring from an image - there the assumption is made that the old drive will be discarded or reformatted and given a different VSN. I don't think having duplicate VSN has any harmful effects.

I think you must be right, because I looked through the old reports from my disk cataloger, and I've had several duplicate VSNs in the past, probably going back several years, and no problems that I'm aware of. So I guess I won't worry about this until the next time I format or image a drive.

Thanks to everyone for the responses.

Yes, the 32 bit ID in the MBR.

Use "DiskPart" in a command shell or powershell tofind the drives "Signature", which is the Unique ID that each drive must have. The "Volume Serial Number" is NOT the same as the "UniqueID" or signature. Here is what you need to type to get what you want.

run cmd.exe
DiskPart
List Disk (To list the disks in your PC)
Select Disk X (Where X is the disk you want to see)
UniqueID Disk

It will reply with something like this:

Disk ID: FA30143E

I had this problem when I copied a whole disk with partitions to an equivalently identical disk. Not sure of the problems I had but it did require changing the disk ID. I can't find the option to change it but I'm pretty sure I managed it via Disk Management. It might have been that I did this via Partition Magic on my XP system however - just can't rmember, sorry.

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Hope that helps someone. I am new to this wonderful site and hope that I am not violating any rules, however I did read them and the only thing is if I posted in the right place.
harmie