PC IDs?

[Projectshifter]

I just recently started helping out again with Graal, and I heard about the PC ids being able to be used and I was kind of impressed, and wondering where exactly these IDs come from? My id was in the 100s when I was on Windows, then I switched over to my Kubuntu (Linux) and it was like 32,000 something. Someone told me that one of their friends had a new PC ID everytime they installed a Windows update, so I figured putting on a new linux distro would change my PC ID but it didn't. I now am running Debian with a 2.6.15 kernel (Kubuntu was 2.6.9) and it's still the same ID.

Where the hell do they come from? I'm assuming the OS has something to do with it, but I thought the original plan is it was to read your hardware and go from there? Anyone else have theirs change after they did something, or not change after they did something major to their system?