Getting a unique hardware ID with Python

You could use dmidecode.

Linux:

import subprocess

def get_id():
    return subprocess.Popen('hal-get-property --udi /org/freedesktop/Hal/devices/computer --key system.hardware.uuid'.split())

Windows:
NOTE: Requires dmidecode for Windows

import subprocess

def get_id():
    return subprocess.Popen('dmidecode.exe -s system-uuid'.split())

Cross-platform:
NOTE: Requires dmidecode for Windows

import subprocess
import os

def get_id():
    if 'nt' in os.name:
        return subprocess.Popen('dmidecode.exe -s system-uuid'.split())
    else:
        return subprocess.Popen('hal-get-property --udi /org/freedesktop/Hal/devices/computer --key system.hardware.uuid'.split())

Please note that you can get the same UUID from Windows without installing any additional software with the following command:

C:\> wmic csproduct get uuid