Inside Windows Product Activation
Hardware Information
As discussed above, the hardware configuration linked to the Installation ID is represented by the two double words H1 and H2.
Bit-fields
For this purpose, the double words are divided into twelve bit-fields. The relationship between the computer hardware and the bit-fields is given in the following table.
double word | offset | length | bit-field value based on |
---|---|---|---|
| |||
H1 | 0 | 10 | volume serial number string of system volume |
H1 | 10 | 10 | network adapter MAC address string |
H1 | 20 | 7 | CD-ROM drive hardware identification string |
H1 | 27 | 5 | graphics adapter hardware identification string |
H2 | 0 | 3 | unused, set to 001 |
H2 | 3 | 6 | CPU serial number string |
H2 | 9 | 7 | harddrive hardware identification string |
H2 | 16 | 5 | SCSI host adapter hardware identification string |
H2 | 21 | 4 | IDE controller hardware identification string |
H2 | 25 | 3 | processor model string |
H2 | 28 | 3 | RAM size |
H2 | 31 | 1 | 1 = dockable, 0 = not dockable |
Bit 31 of H2 specifies, whether the bit-fields represent a notebook computer that supports a docking station. If docking is possible, the activation mechanism will be more tolerant with respect to future hardware modifications. Here, the idea is that plugging a notebook into its docking station possibly results in changes to its hardware configuration, e.g. a SCSI host adapter built into the docking station may become available.
Bits 2 through 0 of H2 are unused and always set to 001.
If the hardware component corresponding to one of the remaining ten bit-fields is present, the respective bit-field contains a non-zero value describing the component. A value of zero marks the hardware component as not present.
All hardware components are identified by a hardware identification string obtained from the registry. Hashing this string provides the value for the corresponding bit-field.