There's a discrepancy on the registry value listed on page 376 to disable IPv6.
Current text: 4. Set its value to 0xFF hex (256 decimal).
The hex and decimal values are not equal. I'm fairly sure that The Good Mark just missed the conversion to decimal, and that the hex value is correct (but the decimal value is incorrect.)
Corrected text: 4. Set its value to 0xFF hex (255 decimal).