Ever since Windows 8, Microsoft stopped putting stickers with the Windows product key on laptops. They would become illegible with time and they were cumbersome to type when (re)installing Windows.

Where is the product key, then?

It’s “burned” into your laptop’s firmware, inside the MSDM ACPI table.

Thankfully, extracting they is relatively easy if you happen to have a Linux on a USB stick lying around.

You can read the contents of the MSDM table by opening the /sys/firmware/acpi/tables/MSDM file with hexdump. It usually begins with some garbage data whose purpose I blissfully ignore and should end with your product key.

Now you can choose to wipe the Windows partition and virtualize it instead of dual booting. Bingo!

Here’s an example, with my data carefully redacted since I’m not in the business of giving away free Windows licenses (G stands for “garbage”, P for “product key”):

[email protected]:~# hexdump -C /sys/firmware/acpi/tables/MSDM
00000000  47 47 47 47 47 47 47 47  47 47 47 47 47 47 47 47  |GGGGGGGGGGGGGGGG|
00000010  47 47 47 47 47 47 47 47  47 47 47 47 47 47 47 47  |GGGGGGGGGGGGGGGG|
00000020  47 00 00 00 47 00 00 00  00 00 00 00 47 00 00 00  |G...G.......G...|
00000030  00 00 00 00 47 00 00 00  50 50 50 50 50 2d 50 50  |....G...PPPPP-PP|
00000040  50 50 50 2d 50 50 50 50  50 2d 50 50 50 50 50 2d  |PPP-PPPPP-PPPPP-|
00000050  50 50 50 50 50                                    |PPPPP|
00000055