Inside Windows Product Activation

Using XPDec

XPDec is a utility to be run from the command prompt. It may be invoked with one of four command line options to carry out one of four tasks.

XPDec -i

This option enables you to access the information hidden in an Installation ID. It decodes the Installation ID, decrypts it, and displays the values of the hardware bit-fields as well as the Product ID of your product. Keep in mind that the last three digits of the Product ID contained in the Installation ID are randomly selected and differ from the Product ID displayed by Internet Explorer.

The only argument needed for the '-i' option is the Installation ID, as in

XPDec -i 002666-077894-484890-114573-XXXXXX-XXXXXX-XXXXXX-XXXXXX-XX

XPDec -p

To help you trace the origin of your Product ID, this option decodes a Product Key and displays the Raw Product Key as it would be used in a Product ID.

The only argument needed for the '-p' option is the Product Key, as in

XPDec -p FFFFF-GGGGG-HHHHH-JJJJJ-KKKKK

Note that this option does not verify the digital signature of the Product Key.

XPDec -v

This option calculates the hash of a given volume serial number. It was implemented to illustrate our description of string hashing. First use '-i' to display the hardware bit-fields. Then use this option to verify our claims concerning the volume serial number hash.

The only argument needed for the '-v' option is the volume serial number of your system volume, as in

XPDec -v 1234-ABCD

(The volume serial number is part of the 'dir' command's output.)

XPDec -m

This option calculates the network adapter bit-field value corresponding to the given MAC address. Similar to '-v' this option was implemented as a proof of concept.

The only argument needed for the '-m' option is the MAC address of your network adapter, as in

XPDec -m 00-C0-DF-08-9E-44

(Use the 'route print' command to obtain the MAC address of your network adapter.)