Service tag not recognised

Question

I have an old Dell laptop, bought new about 10 years ago, which I installed Linux on when I bought a new laptop 5 years ago. It still works fine, although the battery will no longer charge. I now want to reinstall Windows, but the service tag is not recognised. I'm not sure of the model but I think it's an Inspiron 15. I don't want to end up with an unregistered copy of Windows or have to pay Microsoft for the privilege, since a licensed copy of Windows was included with the machine when I bought it. What can I do?

ejn63 · Answer

The service tag database has likely been cleared for a system that old, but it's not needed to do a Windows reinstall. If the system was running Windows 10 (Windows 11 won't be supported on this model due to its age), simply use the Microsoft Media Creation Tool to build a bootable installation flash drive for the system. Once installed, Windows will auto-activate once you go online.

https://support.microsoft.com/en-us/windows/create-installation-media-for-windows-99a58364-8c02-206f-aa6f-40c3b507420d

If the system was running Windows 8 or earlier, note that the OS installation is no longer available for these obsolete operating systems, though you may find installation media elsewhere.

anne_droid · Answer

Hi

If Linux is still active (or runs from a live usb) try .............

Linux
sudo strings /sys/firmware/acpi/tables/MSDM | tail -1

sudo strings /sys/firmware/acpi/tables/MSDM | tail -1
[sudo] password for anne:
ANNIE-DROID-X666T-ANNIE-DROID

It may very well find/show a licence key.

CMD

wmic path softwarelicensingservice get OA3xOriginalProductKey

POWERSHELL
powershell "(Get-WmiObject -query ‘select * from SoftwareLicensingService’).OA3xOriginalProductKey"

ShowKeyPlus - Windows Product Key Information

Product Name: Windows 11 Home

Version: 18362.387 (64-bit OS)

Product ID: 00000-00000-00000-AAOEM

Installed Key: 11111-22222-33333-aaaaa-ZZZZZ

OEM Key: WINDO-WSELE-VENLI-CENCE-KEYDE-LLOEM

OEM Edition: Win 11 RTM Core OEM:DM

Andy Mann · Answer

Thanks, I'll give it a try -- nothing else I can do really.

Andy Mann · Answer

@anne_droid​ No MSDM file. I tried stringing all the other files there just in case, but no luck. Thanks anyway.

anne_droid · Answer

Hi

Methinks I sold you a dud...

Quick check for an embedded key

Open a terminal and run:

bash

sudo strings /sys/firmware/acpi/tables/MSDM

or, if that file exists but the output is messy, try:

bash

sudo cat /sys/firmware/acpi/tables/MSDM

If the board has an OEM key, you should see a 25‑character key in the form XXXXX-XXXXX-XXXXX-XXXXX-XXXXX somewhere in the output.

If you get “No such file or directory” or there is no 25-character key in that table, then there is no embedded OEM Windows key on that mainboard (for example, if it never shipped with Windows, was volume-licenced, or uses only digital entitlement.

Inspiron

Service tag not recognised

Quick check for an embedded key

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