# Difference between Volume IDs and Volume Serial Numbers? And can Volume IDs be addressed?

The Volume Serial Number (VSN) looks like this: 1A79-B12A And can be found using the 'dir' or 'vol' command in Windows without any switches.

Volume GUID looks like this: 4523b23c-5fca-22c5-7ac2-874d7c7e6789 And can be found using the 'mountvol' command in Windows.

And can be accessed by entering this in run: (double backslash) \\?\Volume{4523b23c-5fca-22c5-7ac2-874d7c7e6789}\

My questions are:

1. What are the differences between Volume GUID and Volume Serial Number?
2. Can volumes be accessed using Volume Serial Number?
3. Do Volume GUIDs change on OS REINSTALL (Without Partition formatting)?

Note: From what I'm aware VSN doesn't change on reinstall, only changes on format. Is that the same with VGUID too? Would it be safe for me to address using VGUID (for cross HDD junctions) instead of drive letters?

This article suggests that Windows creates the Volume GUIDs, does it mean that it is not recorded in the MBR and may change after reinstall or it maybe different between two operating systems in a dual boot scenario?

• OS reinstall. I'm not sure what other install is significant enough to change volume GUID – Haneef Ibn Ahmad Jan 5 '18 at 0:19
• I currently have the same issue as this person: windows10forums.com/threads/… I created my junction using drive letters, so, when the OS reboots into the installation files, it fails,because that's technically another OS that has different drive letter assignments. So, if I can have a unique identifier, that doesn't change between OSes or installations. It would be good – Haneef Ibn Ahmad Jan 5 '18 at 0:21
• @JakeGould Thanks. When you say physical volume, are you referring to a physical device like HDD/SSD/USB/CD/DVD? – Haneef Ibn Ahmad Jan 5 '18 at 0:59
• @JakeGould just making sure, if you say, Physical Volumes are Physical Devices and that Physical Devices have have Volume Serial Numbers. I would deduce that to be wrong. You can check this yourself by executing the 'vol' command in different partitions of the same physical device. I think you have mistaken VSN for Disk Serial number. Disk serial number can be obtained by entering the 'wmic diskdrive get serialnumber' command – Haneef Ibn Ahmad Jan 5 '18 at 1:06
• Haneef, you can create your junctions using Volume GUID format to avoid this problem. I've done it this way exclusively for several years on a multi-drive distributed system and the only issue is that chkdsk seems to remove cross-drive junctions if the volume shuts down dirty. There are workarounds for that. The format, which works with linkd is like so: \\?\Volume{30d23498-b8e0-42cb-912d-851eb0fffc7b}\path\to\dir\or\file – Glenn Slayden Jan 6 at 8:39